pericarditis

Inflammation of the pericardium (the thin membrane surrounding the heart). A virus, bacterial infection or fungal infection can cause pericarditis. Other causes include complications from a heart attack or heart surgery, kidney failure, radiation therapy and injury to the chest. Symptoms include chest pain that becomes worse with movement and eases when sitting up or leaning over, fast breathing, cough, fever and chills. Treatment for pericarditis is based on the cause and might include antibiotics, steroids and/or pain medication.

perianal

The area around the anus (the outlet of the rectum).

peptic ulcer

A sore that develops in the lining of the stomach or duodenum (the first portion of the intestine that connects to the stomach). Some possible symptoms of peptic ulcers include indigestion, heartburn, belching, vomiting blood and black tarry stools.

pelvic inflammatory disease

An infection of the female reproductive organs. Pelvic inflammatory disease is often caused by a sexually transmitted disease or bacterial infection.

pediatrician

A pediatrician is a physician who specializes in the care of children. Pediatricians may subspecialize in specific areas of children's health, including adolescent medicine, clinical and laboratory immunology, toxicology, neonatal-perinatal medicine, neurodevelopmental disorders, cardiology, critical care, emergency medicine, endocrinology, gastroenterology, hematology-oncology, infectious diseases, nephrology, pulmonology, rheumatology and sports medicine.

pathologist

A pathologist is a physician who specializes in medical diagnosis by examining tissue, blood or body fluids. Pathologists conduct postmortem exams (autopsies) to determine cause of death. Areas of emphasis include anatomic or clinical pathology. Subspecialty fields include blood banking/transfusion medicine, chemical pathology, cytopathology, dermatopathology, forensic pathology, hematology, immunopathology, medical microbiology, molecular genetic pathology, neuropathology and pediatric pathology.

partial prothrombin time (PTT)

A test that measures blood clotting time.

partial gastrectomy

A method of treating peptic ulcer or cancer by surgically removing the part of the stomach that produces digestive acid.

paroxysmal nocturnal dyspnea

Sudden nighttime shortness of breath, usually a result of fluid in the lungs from congestive heart failure.

parotitis

Inflammation or infection of the parotid gland, the largest of the salivary glands, located below and in front of the ear. Parotitis is a symptom of mumps.

Parkinson's disease

A progressive, degenerative neurological disease often characterized by tremors, muscle rigidity and shuffling gait.

paresthesia

An abnormal skin sensation such as tingling, prickling or burning. Paresthesia is usually related to peripheral nerve damage.

parasympathetic nervous system

The part of the nervous system that dominates during nonstressful situations, slowing the heart rate to normal, aiding the digestive system in normal digestion and regulating saliva secretions, for example.

paralysis

The inability to move a part of the body. Paralysis is usually the result of nerve damage, which can be caused by such things as trauma and stroke.

paracervical block

The injection of a local anesthetic, such as lidocaine, into the tissues around the cervix. During the procedure, an instrument called a speculum is placed into the vagina in order to see the cervix and inject the medication. Paracervical blocks are used to relieve pain during childbirth or gynecological procedures in which the cervix will be dilated (opened).

papilloma

A small, benign (essentially harmless) growth in the skin or a mucous membrane. Warts and polyps are common papillomas.

panic attack

A sudden surge of mounting physiological arousal that can occur out of the blue or in response to encountering (or merely thinking about) a feared situation.

pancreatitis

Inflammation of the pancreas (the gland that produces insulin and some of the enzymes the body needs to digest proteins, carbohydrates and fats). Pancreatitis can be caused by alcoholism, gallbladder disease, abdominal injury or infection. Symptoms include abdominal pain and swelling, vomiting, gas and fever.

pancreas

The gland that produces some of the enzymes (proteins in the body that help create chemical reactions) the body needs to digest proteins, carbohydrates and fats. The pancreas also produces insulin, which helps regulate blood sugar in the body.

palate

The roof of the mouth.

Paget's disease

A chronic disease of the skeleton characterized by rapid bone turnover. Also known as osteitis deformans.

ovaries

The female glands that produce female sex hormones (estrogen and progesterone) and eggs for reproduction.

otosclerosis

A disorder caused by an abnormal growth of spongy bone at the entrance to the inner ear. Otosclerosis results in gradual hearing loss.

otolaryngologist

An otolaryngologist is a physician who specializes in conditions of the ear, nose and throat. This type of physician may also be referred to as an ear, nose and throat (ENT) specialist. Subspecialty fields include otology/neurology, pediatric otolaryngology and plastic surgery.

osteomyelitis

Inflammation of bone or bone marrow caused by a bacterial infection. Symptoms of osteomyelitis may include pain, fever and fatigue.

osteoclast

The type of cells that break down bone.

osteoblast

The type of cells that build up bone.

osteitis deformans

A chronic disease of the skeleton characterized by rapid bone turnover. Also known as Paget's disease.

orthopedist

An orthopedist is a physician who specializes in the prevention and correction of conditions of the skeleton, joints, muscles and supporting structures, such as ligaments and cartilage. Hand surgery is one subspecialty area.

oral lichen planus

Small, pale pimples or shiny, raised patches appearing on the sides of the tongue or inside the cheeks. This rare disorder may also affect the skin.

optometrist

An optometrist is a health professional who examines patients' eyes, prescribes and fits eyeglasses and contact lenses, and may recommend eye exercises and other treatments. To become an optometrist, you must complete a one- to three-year college program that focuses on math and science and earn a four-year university degree in optometry.

opportunistic infection

A bacterial, viral or fungal infection that occurs because the body's immune system is not functioning properly.

ophthalmologist

An ophthalmologist is a physician who specializes in conditions of the eyes.

oophorectomy

The surgical removal of both ovaries (the female glands that produce female sex hormones and eggs for reproduction).

oncologist

An oncologist is a physician who specializes in the care of people who have cancer. Many oncologists are also trained in hematology (treatment of conditions of the blood and the blood-forming tissues of the body).

omentum

A sheet of fat that encloses the intestines. The greater omentum is attached to the bottom of the stomach and hangs down in front of the intestines. The lesser omentum is attached to the top of the stomach and extends to the bottom of the liver.

obstetrician/gynecologist

An obstetrician/gynecologist is a physician who specializes in conditions of the female reproductive organs and women's health. This type of physician can also provide care to women during pregnancy, childbirth and the postpartum period (after a baby is born). Subspecialty fields include critical care medicine, gynecologic oncology, maternal and fetal medicine, and reproductive endocrinology.

obsessive-compulsive disorder (OCD)

A type of anxiety disorder characterized by obsessions, which are thoughts that provoke anxiety, and compulsive behaviors, which are temporary but ineffective behavioral attempts to reduce the anxiety.

nurse practitioner

A registered nurse who has received further training in a particular field, such as pediatrics or gynecology. This education is usually completed through a college or university, where the person receives a master's degree in nursing.

norepinephrine

A hormone secreted by the adrenal gland that causes constriction of blood vessels, as well as increases in heart rate, blood pressure and blood sugar levels.

nonsteroidal anti-inflammatory drugs (NSAIDs)

Drugs that decrease tissue inflammation. NSAIDs may also reduce pain and fever.

nighttime eating disorder

A type of sleep disorder characterized by recurring episodes of altered alertness in which a person engages in rapid binge-eating while asleep without being aware of it.

newborn

An infant less than 1 month old; also called a neonate.

neurotransmitter

A substance that carries signals in the brain.

neurosurgeon

A neurosurgeon is a physician who specializes in surgery of the brain and nervous system.

neuropathy

Inflammation or degeneration of nerves. Generally, neuropathy refers to any condition or disease of the nervous system or any of its components.

neurologist

A neurologist is a physician who specializes in conditions of the nervous system (the pathways of the brain and spinal cord that transmit and receive electrical impulses to and from the skin, muscles, joints and sensory areas, such as sight, hearing, taste and smell). Subspecialty fields include child neurology, clinical neurophysiology, neurodevelopmental disorders and pain management.

neurological

Relating to the nervous system, including the brain and spinal cord.

neurological

Relating to the nervous system, including the brain and spinal cord.

neuralgia

The term for sudden, shooting, usually intense pain along a nerve, sometimes described as a sudden, severe spasm. Neuralgias vary in terms of frequency, duration, causes and locations in the body.

nephrologist

A nephrologist is a physician who specializes in conditions of the kidneys.

nephritis

Inflammation of the kidneys.

neonatologist

A neonatologist is a physician who specializes in conditions affecting newborns. Neonatologists receive intensive training focused on high-risk pregnancies, birth and post-birth care. Neonatologists often consult with both obstetricians and pediatricians in the delivery and post-birth stages of care.

neonate

An infant up to 6 weeks old; also called a newborn.

necrosis

Death of cells or tissues through injury or disease.

nasogastric suction

The removal of fluids and gas from the stomach through a tube inserted through the nose that extends down into the stomach.

narcotics

The term for drugs that produce stupor or sedation by depressing the central nervous system. Narcotics are sometimes prescribed to relieve pain or induce sleep.

myositis

Inflammation of muscle tissue; also called myitis.

myoma

A tumor composed of muscle tissue.

myocarditis

Inflammation of the heart muscle. Myocarditis is usually a secondary effect of an underlying condition.

myocardial infarction

When an area of heart muscle dies or is damaged due to a lack of blood flow and oxygen to that area; also called MI or heart attack.

myelography

An X-ray examination used to evaluate the spinal cord and nerve roots for suspected compression. During the procedure, a special contrast dye is injected through a needle into the space around the spinal cord, the needle is removed, and X-rays are taken.

myelin sheath

The protective coating on nerve fibers that carry electrical impulses away from the nerve's cell body to the brain and spinal cord. The myelin sheath protects the nerves and speeds up the conduction of impulses along the nerve cells. Without myelin, electrical impulses are slowed and can become completely blocked.

myasthenia gravis

An incurable autoimmune disease (a condition in which the body produces antibodies to fight against its own tissues) marked by weakness and fatigue, particularly among the skeletal (voluntary) muscles.

myalgia

Muscle pain or tenderness.

muscle relaxant

A drug given to relax muscles (usually skeletal) that are in spasm or tight continuous contractions.

murmur

A blowing, whooshing or rasping sound created by abnormal blood flow in the heart. Murmurs can occur when a heart valve does not close tightly or when blood flows through a narrowed opening in the heart. Murmurs are heard by listening to the chest with a stethoscope.

Munchausen syndrome by proxy

A psychological disorder in which a caregiver causes or feigns physical or psychological symptoms in another person in order to receive medical attention.

mumps

A contagious, systemic (affecting the body as a whole) viral disease characterized by swelling and tenderness of the salivary glands, particularly the parotid gland (the largest of the salivary glands, located below and in front of the ear).

multipara

A woman who has given birth before.

motion sickness

A disturbance of the inner ear caused by motion, such as from movement of a car, plane or ship. Motion sickness affects the sense of balance and equilibrium in the inner ear. Symptoms of motion sickness include nausea, vomiting and dizziness.

monounsaturated fatty acid

A fatty acid missing one pair of hydrogen atoms in the middle of the molecule. The gap is called an "unsaturation." Monounsaturated fatty acids are found mostly in plant and sea foods. Olive oil and canola oil are high in monounsaturated fatty acids. Monounsaturated fatty acids tend to lower levels of LDL cholesterol (the "bad" kind) in the blood.

mononucleosis

A contagious viral infection; the main symptoms are fever, fatigue, sore throat and enlarged lymph nodes in the neck (the small, round structures that help protect the body from invasion by bacteria or other organisms). The most common cause is Epstein-Barr virus

mittelschmerz

Lower abdomen and pelvic pain, in the middle or to one side, that some women experience during ovulation. Mittleschmerz pain can range from a mild twinge to severe discomfort and usually lasts from several minutes to several hours.

mitral valve

The valve between the left atrium (the upper left chamber of the heart) and the left ventricle (the lower left chamber of the heart). The mitral valve keeps blood from flowing back into the left atrium. It's also called the bicuspid valve because it's made up of two triangular flaps of tissue.

mitral regurgitation

A disorder in which blood flows backward from the left ventricle into the left atrium of the heart due to failure of the mitral valve to close completely.

middle ear

The space, usually filled with air, behind the eardrum. The middle ear contains three small bones that send sound waves from the eardrum across the middle ear to the inner ear.

micrognathia

An abnormally small jaw.

microcephaly

An abnormally small head and underdeveloped brain.

metabolism

The body's rate of function. Metabolism is the sum of all the physical and chemical processes that create and maintain a living organism.

metabolic alkalosis

A blood chemical imbalance usually resulting from excessive loss of stomach or kidney acids, loss of potassium due to diuretics (drugs that increase urination), or severely hyperactive adrenal glands.

meningoencephalitis

Inflammation of the brain and meninges (membranes covering the brain) usually caused by a virus. Symptoms include high fever, headache, nausea and vomiting, and stiff neck.

melanin

A pigment that determines skin, hair and eye color. Sunlight exposure stimulates melanin production.

median nerve

The nerve that supplies sensation to the thumb, index finger, middle finger and usually half of the fourth finger (ring finger). The median nerve also provides nerve input to muscles of the thumb area. This nerve travels through the carpal tunnel area.

meconium

A baby's first stool. Meconium is usually thick, sticky and dark green.

measles

A highly contagious viral infection that affects the respiratory tract and skin.

mastoiditis

Inflammation of the round bone behind the ear.

mastitis

Inflammation of the breast tissue. Mastitis is most common in breastfeeding women in the second or third week after giving birth.

mastectomy

Surgical removal of a breast.

marriage and family therapist

A marriage and family therapist is a mental health professional who works with individuals, couples and families on a variety of mental health issues. The focus is helping people within the context of family. A marriage and family therapist must have at least a master's degree in marriage and family therapy or a related field and complete a set amount of supervised work.

Marfan's syndrome

An inherited disorder of connective tissue that affects many parts of the body, including the skeleton, lungs, eyes, heart and blood vessels.

mammoplasty

Surgical reconstruction of the breast.

mammary

Relating to the breast.

magnetic resonance imaging (MRI)

A diagnostic test that provides cross-sectional images of organs and structures inside the body using a magnetic field and radio waves rather than X-rays or radiation.

macula

A small area in the center of the retina (the light-sensitive tissue at the back of the eye that sends nerve impulses to the brain); the macula is responsible for central vision.

Ménière's disease

A recurrent and typically progressive group of symptoms including severe attacks of dizziness, tinnitus (ringing in the ears), progressive deafness and a feeling of pressure in one or both ears.

lymph nodes

Small, bean-shaped organs located throughout the body, particularly in the neck, armpit and groin that filter bacteria and foreign particles from the body.

lumbar region

The lower back.

lumbar puncture

A procedure to obtain a sample of cerebrospinal fluid for diagnostic testing. During the procedure, a needle is inserted into the spinal column in the lumbar region (lower back), and a small amount of cerebrospinal fluid is removed.

lower esophageal sphincter

The valve between the esophagus (the tube that connects the throat and stomach) and the stomach.

lochia

Vaginal discharge after childbirth that contains blood, mucus and tissue from the uterus. The discharge may last up to six weeks after delivery.

local anesthesia

The numbing of a small or limited area of the body.

lobe

A well-defined portion of an organ separated by connective tissue, a crack or a groove.

liver

A large organ located in the right upper quadrant of the abdominal cavity. The liver helps the body eliminate toxins and waste from the body and plays a role in metabolism. The liver also secretes bile which helps the body digest fats.

lipoma

A lump or benign tumor made up of fatty tissue.

lipid

A chemical compound characterized by the fact that it is insoluble in water. Both fat and cholesterol are members of the lipid family.

ligament

A strong sheet or band of fibrous tissue that connects bones or cartilage at a joint. Ligaments support and strengthen joints.

Lewy bodies

Abnormal brain cells present in certain diseases of the nervous system.

leukopenia

A low white blood cell count. Often, leukopenia is related to an infectious disease or the use of a certain medication or chemical.

leukemia

An uncontrolled, malignant (abnormal) growth of white blood cells in bone marrow.

lesion

A wound, injury or diseased area of skin.

lens

The clear part of the eye behind the iris that helps to focus light on the retina. The lens helps to focus objects so they appear sharp and clear.

left coronary artery

The main source of blood to the left ventricle (the main pumping chamber of the heart).

laxative

A food or medication that stimulates evacuation of the bowels and relieves constipation.

lateral epicondylitis

A condition characterized by pain and inflammation near the elbow and around that outer side of the arm and forearm that develops from overuse of forearm muscles and tendons; also known as tennis elbow.

larynx

The organ of voice, located at the top of the trachea and below the base of the tongue. The larynx is commonly referred to as the voice box.

laparotomy

A surgical incision in the abdominal area. Also, a general term for abdominal surgery.

lactate dehydrogenase (LDH)

An enzyme present in various tissues that can be measured for certain diagnostic tests. For example, blood levels of LDH rise within 24 to 72 hours after a heart attack.

laceration

A jagged cut or wound.

labia

The folds of skin and tissue on either side of the vaginal opening and the external female genitals. The labia majora meet above the clitoris and extend to the perineum (the area between the vaginal opening and anus). The labia minora lie just inside the labia majora, surrounding the vaginal opening.

kidney

One of a pair of organs located in the upper rear portion of the abdominal cavity. The kidneys are part of the urinary tract and are responsible for removing waste products from the blood, regulating electrolytes, and maintaining water balance in the body by excreting urine.

kernicterus

Brain damage caused by deposits of bilirubin in the brain. Kernicterus develops in extremely jaundiced newborns; premature infants are at greatest risk. Kernicterus can lead to brain damage, muscle disorders, hearing loss, seizures or even death.

keratosis

Scaly, hard skin growths, usually yellow, brown, gray or black in color.

keloid

Raised, firm scar tissue on the skin. Keloid tissue can result from surgical incisions, cuts, abrasions, piercings, vaccinations, burns or other forms of skin trauma.

Kegel exercises

Exercises used to strengthen the pelvic muscles that support the bladder, uterus and rectum. Kegel exercises involve the voluntary tightening and relaxation of the pelvic muscles. Kegel exercises can help reduce urinary incontinence or leakage.

Kaposi's sarcoma

A rare cancer characterized by discolored patches on the skin or mucous membrane tissues. Kaposi's sarcoma occurs most commonly in people who have AIDS.

juvenile rheumatoid arthritis

A form of chronic rheumatoid arthritis affecting children under age 16. Rheumatoid arthritis is an autoimmune disease (when the body produces antibodies to fight against its own tissues) in which certain joints and connective tissues are inflamed. It most often affects the joints of the hands and feet.

ischemic stroke

A stroke caused by ischemia (diminished blood flow) to the brain or part of the brain.

ischemia

A temporary lack of blood and oxygen to the tissues.

iron-deficiency anemia

Anemia is a condition marked by a decreased number of red blood cells or hemoglobin (a protein in red blood cells that contains iron); the red blood cells carry oxygen throughout the body. Iron-deficiency anemia develops when the amount of iron stored in the body does not meet the body's demand for iron.

iris

The colored part of the eye.

intravenous pyelogram (IVP)

An X-ray (an electromagnetic wave sent through the body that creates an imageof internal body parts on film) of the kidneys taken after the patient is injected with a contrast dye. The procedure helps the doctor determine if stones, a tumor or anatomic abnormalities are restricting or blocking urine flow, as well as find stones that may be missed with a standard X-ray.

intravenous

Within or into a vein.

internist

An internist is a physician who specializes in the primary care of adults. There are many subspecialty fields within internal medicine:

Adolescent medicine specialists care for adolescents.

Cardiologists treat conditions of the heart. Related subspecialties are clinical cardiac electrophysiology and interventional cardiology.

Endocrinologists treat conditions of the endocrine glands (those that produce hormones), including the pituitary, thyroid, parathyroid and adrenal glands, as well as the pancreas, ovaries and testes. These glands are responsible for growth, metabolism, sexual maturity, reproduction and resistance to stress and disease.

Gastroenterologists specialize in conditions of the stomach, intestines, esophagus, liver, gallbladder and pancreas.

Hematologists specialize in conditions of the blood and the blood-forming tissues of the body. Many hematologists are also trained in oncology (the care of people who have cancer).

Infectious disease specialists specialize in diseases caused by microorganisms.

Nephrologists specialize in conditions of the kidneys.

Oncologists specialize in the care of people who have cancer. Many oncologists are also trained in hematology.

Pulmonologists specialize in conditions of the lungs.

Rheumatologists specialize in conditions of the muscles, joints, ligaments and cartilage, such as arthritis.
Internists can also obtain certificates of added qualification in geriatrics, clinical and laboratory immunology, critical care medicine and sports medicine.

insomnia

The inability to fall asleep or stay asleep.

inguinal canal

A passageway in the lower abdomen that opens into the groin.

infectious disease specialist

An infectious disease specialist is a physician who specializes in diseases caused by microorganisms. Some diseases typically treated by infectious disease specialists include AIDS, hepatitis and malaria.

infarction

Death of an area of tissue after blood supply is cut off

incontinence

The inability to control the release of urine or feces.

impacted tooth

A poorly positioned tooth that can't grow through the gum normally.

immunosuppressant

A drug that suppresses the body's immune system or activation of immune responses.

immunoglobulin

A protein that can act as an antibody (a compound that helps neutralize or destroy foreign substances in the blood).

immunity

Resistance to a disease through the body's immune system; can be present at birth or develop after immunization or infection with the disease.

ileostomy

A surgical procedure in which a passage is created from the outside of the body through the abdominal wall into the ileum (the end of the small intestine). A urinary ileostomy is a passage created between the urinary bladder and the ileum.

ileitis

Inflammation of the ileum, the last section of the small intestine.

hypoxemia

A lack of oxygen in the blood.

hypothyroidism

A condition in which the thyroid gland is underactive and does not produce a sufficient amount of thyroid hormones.

hypothermia

A lower than normal body temperature, usually caused by prolonged exposure to cold, which can be a serious or life-threatening condition. Sometimes hypothermia is deliberately induced during certain surgical procedures.

hypothalamus

The part of the brain that produces and releases hormones that help control certain metabolic functions, such as maintaining water balance, metabolizing fat and sugar, and regulating body temperature.

hypotension

Low blood pressure, or a decrease in blood pressure.

hypospadias

A penis abnormality in which the opening of the urethra (the tube that carries urine and semen to the outside of the body) is located on the underside of the penis rather than at the end.

hypokalemia

Low potassium in the bloodstream.

hypochloremic alkalosis

A chemical imbalance of the blood caused by severe loss of salt due to sweating or vomiting.

hypocalcemia

An abnormally low level of calcium in the blood.

hyperthyroidism

A condition in which the thyroid gland is overactive and releases an overabundance of thyroid hormones into the bloodstream.

hyperhidrosis

Excessive sweating.

hypercalcemia

An abnormally high concentration of calcium in the blood.

hyperbaric chamber

An airtight enclosure strong enough to withstand high internal pressure. A hyperbaric chamber may be used to treat decompression sickness by shrinking air bubbles and allowing them to pass through the blood vessels.

hymen

A fold of mucous membrane that partly covers the vaginal opening. Contrary to traditional belief, the absence or presence of the hymen cannot prove or disprove a female's virginity.

hydrops

The collection of an excessive amount of fluid in body tissues.

hydrogenated fat

A fat that has been chemically altered by the addition of hydrogen atoms. Common examples of hydrogenated fat include vegetable shortening and margarine.

hydrocephalus

An abnormal accumulation of cerebrospinal fluid in and around the brain that may result in decreased circulation of the fluid and efficiency of brain function. Hydrocephalus may be caused by developmental abnormalities, infection, injury or other medical conditions.

hydramnios

Excessive amniotic fluid (the fluid that surrounds and protects a fetus in the womb).

humerus

The upper arm bone, extending from the shoulder joint to the elbow.

hormone

A substance originating in an organ or other body part. Hormones are transported to other parts of the body to chemically increase or decrease functional activities and/or the secretion of other hormones.

Holter monitoring

Continuously recording the heart's electrical activity for 24 hours through a small battery-powered device worn by the patient.

Hodgkin's lymphoma

A tumor of the lymph system (the system that helps protect the body from invasion by bacteria or other organisms. Hodgkin's lymphoma generally involves the lymph glands (structures of the lymph system that produce immune substances), lymphocytes (white blood cells) and spleen (one of the organs involved in the storage and production of blood cells).

hiatus

An opening or aperture. The hiatus in the diaphragm (the muscle that separates the chest cavity from the abdominal cavity) is an opening through which the esophagus (the tube that connects the throat and stomach) passes.

herpes simplex

An infection caused by the herpes simplex virus that affects the skin and nervous system. There are two types of herpes simplex virus. The type 1 virus causes cold sores, which develop shortly after exposure and most commonly affect the lips, mouth, nose, chin or cheeks. The type 2 virus typically causes genital sores and most often spreads through sexual contact with an infected person.

herniorrhaphy

The surgical repair of a hernia (a tear in the abdominal muscle wall).

hernioplasty

The surgical repair of a hernia (a tear in the abdominal muscle wall).

hernia

The protrusion of an organ or other structure into surrounding tissue; usually refers to an abdominal hernia, in which some of the abdominal contents (such as intestines) protrude through a tear in the abdominal muscle wall.

hemosiderosis

A condition in which there are deposits of hemosiderin (a pigment that contains iron and comes from the disintegration of hemoglobin from red blood cells) in the body tissues, particularly in the liver and spleen.

hemorrhage

Excessive bleeding, internally or externally, caused by damage to a blood vessel.

hemophilia

An inherited disorder that causes abnormal bleeding due to a blood-clotting factor deficiency. Symptoms range from increased bleeding after injury to sudden bleeding with no visible cause.

hemolytic uremic syndrome

A condition that affects the blood and blood vessels, resulting in the destruction of blood, anemia and kidney failure due to damage to the very small blood vessels of the kidneys. Other organs, such as the brain or heart, may also be affected from the damage. Usually occurs in children after an illness involving diarrhea. Symptoms include very pale skin, lack of energy and decreased urination.

hemolytic anemia

The destruction of red blood cells. Hemolytic anemia is often related to an infection, an inherited disorder or a drug reaction.

hemolytic

Pertaining to the breaking down of red blood cells.

hemoglobin

A protein in the red blood cells that contains iron.

hemodialysis

A procedure that cleans the blood and removes waste and excess water from the body of patients who have chronic kidney failure. During hemodialysis, the patient's blood is circulated through a machine, which contains a dialyzer -- often called an artificial kidney. The dialyzer has two chambers separated by a thin membrane. Excess water and waste pass from the blood through the membrane into the dialysis fluid, which is discarded. The cleaned blood is then returned to the patient's bloodstream.

hemochromatosis

A genetic condition in which there is excessive absorption and accumulation of iron in the body.

hematologist

A localized swelling filled with blood, usually clotted, resulting from a break in a blood vessel.

Helicobacter pylori (H. pylori)

The bacterium that causes most peptic ulcers (sores that develop in the lining of the gastrointestinal tract).

heatstroke

A severe heat-related condition that occurs when the body is unable to regulate its temperature. Symptoms of heatstroke include very dry, hot skin with no sweat, headache, high fever, confusion and rapid heart rate. Heatstroke is a medical emergency.

heat exhaustion

A condition caused by excessive heat and loss of significant amounts of body fluids through sweating. Symptoms of heat exhaustion include weakness, paleness, dizziness, nausea, vomiting and lightheadedness. Mild cases can be treated at home by staying in a cool place, applying ice packs, and drinking fluids.

heart block

An abnormal heart rhythm caused by a slowing of the electrical current between the atria and ventricles of the heart. If the current is completely blocked, the atria and ventricles beat independently.

Hashimoto's disease

An autoimmune disorder in which the body's immune system produces antibodies that attack the thyroid gland. Also known as chronic autoimmune thyroiditis, Hashimoto's disease is the most common cause of hypothyroidism (underactive thyroid).

hantavirus

A virus carried by rodents that can cause a severe respiratory infection and hemorrhagic fever in humans.

hand, foot and mouth disease

A common childhood illness characterized by fever, sores in the mouth and a rash with blisters. Begins with a low fever, decreased, appetite, fatigue and often a sore throat. One to two days later sores develop in the mouth on the tongue, gums and inside of the cheeks. The skin rash develops over several days and has the appearance of raised red spots, some with blisters, on the palms of the hands and soles of the feet. There is no specific treatment.

hammertoe

A deformity in one of the toe joints, most often the second toe. Hammertoe is often caused by wearing tight or poorly fitting shoes.

hallucination

A false sensory perception (such as with hearing, smell, touch, sight, etc.) which occurs without real external stimulation of the relevant sensory organ.

guardian ad litem

A person who represents and advocates for a child's best interest during the legal process.

growing pains

Pain most commonly noticed in the thighs or calves caused by differences in growth rates of muscle, bone and soft tissue. Growing pains are common among rapidly growing children and can last an hour or two at a time, often awakening a child from sleep. Growing pains do not cause fever or swelling, and are not harmful.

gravel

Small concentrations of mineralized salts from the kidneys or bladder. Gravel are smaller than "stones" of the kidney or bladder.

gout

A form of arthritis caused by the deposit of uric acid crystals in a joint. The uric acid crystals cause the joint to become swollen, red, tender and painful. Individuals with gout usually have pain in one or two joints, most commonly the big toe, foot, ankle or knee. Gout attacks can last anywhere from a few days to as long as several weeks.

gonorrhea

A highly contagious sexually transmitted disease characterized by painful urination and yellowish pus-like discharge from the vagina or penis; symptoms are often mild, but untreated gonorrhea can cause severe medical problems, especially for women.

gold compounds

Medicines that use gold as their base. Gold compounds are typically used to treat joint or arthritic disorders. For example, they're thought to influence certain enzyme activities, immune response and phagocyte activity, all of which are altered when you have rheumatoid arthritis.

goiter

A swelling in the front part of the neck caused by enlargement of the thyroid gland (the gland that helps, in part, regulate the body's metabolism). Goiters are primarily caused by dietary iodine deficiencies or other conditions, including infection-related inflammation and decreased or increased functioning of the thyroid gland.

glycosuria

The abnormal presence of sugar in the urine. Glycosuria is a symptom of diabetes mellitus.

gluten

A mixture of protein components found in wheat and other grains. People who have celiac sprue (an intestinal disease caused by gluten intolerance) must follow a gluten-free diet, which involves avoiding food products containing wheat, buckwheat, rye, oats and barley.

glucose

A sugar found in certain foods, especially fruits and in the blood of all humans. Carbohydrates are metabolized into glucose. Glucose is the chief source of energy for the human body.

glossitis

Inflammation of the tongue. Glossitis is generally caused by infection, trauma or burns to the tongue. Symptoms include soreness, swelling and tenderness of the tongue, as well as difficulty speaking, eating, swallowing and breathing.

glucose

A sugar found in certain foods, especially fruits and in the blood of all humans. Carbohydrates are metabolized into glucose. Glucose is the chief source of energy for the human body.

glossitis

Inflammation of the tongue. Glossitis is generally caused by infection, trauma or burns to the tongue. Symptoms include soreness, swelling and tenderness of the tongue, as well as difficulty speaking, eating, swallowing and breathing.

glomerulonephritis

Inflammation of the glomerulus (group of capillaries) of the kidney, usually as a result of an infection. Symptoms of glomerulonephritis include decreased urination, blood and protein in the urine, and swelling of the feet, ankles and hands.

gliadin

One of the proteins found in gluten, a mixture of protein components found in wheat and other grains. Gliadin is a common food additive in products such as flour, monosodium glutamate and cereal. Some people are unable to digest gliadin, which results in damage to the lining of the intestines and an intestinal disease known as celiac sprue.

glans penis

The rounded head of the penis.

gland

The basic term for a structure or organ that releases and potentially manufactures a substance or substances to be used elsewhere in the body.

genital warts

A sexually transmitted disease caused by the human papillomavirus (HPV). Most HPV infections have no visible signs or symptoms, but may cause abnormal cell growth on the female cervix. Visible signs and symptoms of the virus range from soft, pink, cauliflower-like warts to hard, smooth, yellow-gray warts. Women may develop warts inside the vagina, on the external genitals and around the anus. Men usually develop warts on the penis, on the scrotum and around the anus. Symptoms can develop anytime from three weeks to six months after intimate contact with an infected person. Doctos can remove warts by freezing them, burning them with an acidic chemical, or by laser surgery.

genital herpes

An infection caused by the herpes simplex virus that affects the skin and nervous system. There are two types of herpes simplex virus. The type 1 virus causes cold sores, which most commonly develop shortly after exposure and affect the lips, mouth, nose, chin or cheeks. The type 2 virus typically causes genital sores and most often spreads through sexual contact with an infected person.

general anesthesia

Loss of consciousness through injection or inhalation of drugs into the bloodstream or muscles.

gastroscopy

A procedure used to examine the inside of the stomach.

gastroparesis

The temporary or permanent loss of movement, function and/or sensation to the gastrointestinal tract, particularly the stomach. The condition may be partial or complete.

gastrointestinal tract

Includes the esophagus (the tube that connects the throat and stomach), stomach, and small and large intestines (the organs that assist in the digestion and reabsorption of water, as well as form the by-products of digestion into feces).

gastroesophageal reflux disease (GERD)

A chronic condition in which the lower esophageal sphincter (the valve between the bottom of the esophagus and the top of the stomach) allows stomach acid to flow backward into the esophagus. This causes heartburn, acid indigestion and possible injury to the lining of the esophagus.

gastroenterologist

A gastroenterologist is a physician who specializes in conditions of the stomach, intestines, esophagus, liver, gallbladder and pancreas

gastroenteritis

Inflammation of the stomach and intestinal tract that can cause vomiting, diarrhea or both. Gastroenteritis is typically caused by viruses or bacteria found in food and water.

gastritis

Inflammation of the lining of the stomach. Gastritis may be caused by certain drugs, infections or excess acid. Symptoms include abdominal discomfort, nausea, vomiting and/or diarrhea.

gastric

Referring to or associated with the stomach.

gangrene

The death of body tissue.

gallstones

Stone-like masses located in the bile duct or gallbladder (the sac located under the liver; the gallbladder stores bile excreted from the liver and sends it to the small intestine during digestion). Gallstones are usually composed of cholesterol, bile pigments (a bitter-tasting fluid made in the liver that helps the body digest fats) and/or calcium salts.

gallbladder

The sac located under the liver that stores bile (a fluid made in the liver that helps the body digest fats) and sends it to the small intestine during digestion.

fundoplication

Surgery to repair a hiatal hernia (the protrusion of part of the stomach from its normal position in the abdomen through the diaphragm, the muscle that separates the chest cavity from the abdominal cavity). During surgery the upper part of the stomach, the fundus, is wrapped around the lower part of the esophagus and sutured in place.

frozen shoulder

Stiff, painful, limited movement of the shoulder caused by inflammation and thickening of the tough fibrous tissue that surrounds the joint. Frozen shoulder is often related to pain or injury that causes a person to limit movement of the shoulder. Without regular movement, the joint becomes tight and stiff. Treatment for frozen shoulder includes anti-inflammatory pain relievers, mild stretching exercises and the application of heat.

frostbite

Tissue damage resulting from exposure to extreme cold.

fragile X syndrome

A condition caused by a mutation of the X chromosome. Fragile X syndrome is the most common inherited cause of mental retardation. The condition may also cause large ears, chin and forehead, and, for males, enlarged testes.

foreskin

The loose skin (also called the prepuce) covering the end of the penis, for men, or clitoris, for women. Removal of the foreskin is called circumcision.

foramen

Spaces between the vertebrae (the bony sections that make up the spine) through which nerves from the spinal cord exit the spinal canal (a space in the center of the vertebrae).

fontanel

The soft spots on the top of a baby's head -- both front and back -- where the developing skull bones are still separated. Each fontanel is covered by a thick fibrous layer and is safe to touch gently. These areas, which allow for rapid brain growth during infancy, progressively close between ages 2 months and 26 months. The front fontanel typically closes more slowly than the back fontanel.

folic acid

A vitamin that helps produce red and white blood cells. Folic acid also helps prevent certain birth defects, such as anencephaly (the absence of all or part of the brain at birth) and spina bifida (a birth defect affecting the walls of the spinal canal). Folic acid is found in citrus fruits, dark green leafy vegetables, dried beans, liver and whole grain products.

fluorosis

A condition caused by excessive fluoride intake or use, often characterized by discolored tooth enamel. Fluorosis is often caused by excessive amounts of fluoride in drinking water.

fissure

A crackle sore or ulcer in the skin or a crack in the enamel of a tooth.

fifth disease

A contagious viral infection also known as erythema infectiosum. The condition is called fifth disease because it's number five in a group of childhood diseases that cause fever and widespread rash. The rash starts as bright red cheeks, and then spreads to the trunk, buttocks, arms and legs, where it takes on a lacy appearance.

fibula

The smaller of the two bones in the lower leg, between the knee and the ankle. The tibia is the larger of the two bones.

fibroid tumor

A noncancerous tumor of connective and muscular tissue; fibroids are often found in the uterus (the female reproductive organ that houses the embryo and fetus during pregnancy).

fibrocystic breast changes

Normal changes in breast tissue that may cause pain, lumpiness or cysts (pockets of fluid) in the breast.

fibroadenoma

A noncancerous lump made of fibrous and glandular tissue. Fibroadenomas are most commonly found in the female breast.

fibrillation

Rapid, uncoordinated twitching movements that replace the normal rhythmic contractions of the heart. In some cases, fibrillation can cause loss of blood circulation. This may be fatal if not treated promptly.

fibrillation

Rapid, uncoordinated twitching movements that replace the normal rhythmic contractions of the heart. In some cases, fibrillation can cause loss of blood circulation. This may be fatal if not treated promptly.

femur

The thigh bone, extending from the hip to the knee.

fecal occult blood

A small amount of blood in the stool that's not visible to the naked eye. Fecal occult blood can be a sign of a problem in the digestive system, such as a growth, polyp or cancer in the colon or rectum.

fecal impaction

A condition in which feces become tightly wedged in the intestines.