Hair loss or thinning

Definition
Human hair originates from individual hair follicles, which are attached to cells that form the outermost layer of skin. Each strand of hair grows for a period of time, rests, sheds and is then replaced. About 100 to 150 hairs are typically shed each day. Alopecia (hair loss or thinning) occurs when the hair follicles are damaged or the natural replacement hair does not balance the shedding hair. Hair loss without associated scarring is often temporary.

Causes/Associated factors
There are many types of hair loss or thinning, each has its own causes, symptoms, prognosis and treatment.
Androgenetic alopecia, also known as male or female pattern baldness or common baldness, is the most common form of hair loss. It's typically noticed as gradual hair thinning. The condition is generally hereditary. For men, this type of hair loss typically begins around age 20 and affects the area above the forehead, over the temples or the crown. In women, it typically begins later in life and affects the area above the forehead or the crown. For some women, it may simply be noticed as diffuse thinning. Treatment success is highly individual.

Alopecia areata produces complete hair loss in small round patches on the scalp, beard, eyebrows, eyelashes and, less commonly, other areas. This type of hair loss develops suddenly and has an unpredictable course that often resolves without treatment. The cause is unknown, but it's thought to be an autoimmune disorder. Recurrences are common.

Telogen effluvium, also known as stress alopecia, is characterized by excessive generalized hair loss. It occurs after a physical stress to the body, such as pregnancy, surgery, a crash diet or stopping birth control pills. It may also be a side effect of many medications, including amphetamines, coumadin, lithium, levodopa and propranolol.

Anagen effluvium results in scattered hair loss that can lead to extensive balding. This type of hair loss is a side effect of certain types of cancer chemotherapy drugs. It's normally reversible.

Traction alopecia occurs when the hair is pulled too tightly for prolonged periods of time, such as when you wear your hair tightly braided or pulled back, you set rolling curlers too tightly, or you twist your hair repeatedly with your fingers. This type of hair loss can result in scarring, which may lead to permanent hair loss.

Alopecia cicatrisata, also known as cicatricial scarring alopecia, results in smooth, shiny, scarred hairless patches of various sizes. This type of hair loss can be caused by a bacterial, viral or fungal infection, as well as certain skin conditions or injuries, such as burns or trauma. Sometimes, no underlying cause is found. Alopecia cicatrisata is usually irreversible.

Trichotillomania is a disorder characterized by the uncontrollable urge to pull your own hair. With this condition, built-up tension results in such excessive hair pulling that the hair is actually pulled out. The act of pulling out the hair provides relief to the mounting tension. The side of the head that corresponds to the dominant hand is most often affected. Trichotillomania is most common in girls under age 10, but it may occur in boys and older children as well. The condition may be a manifestation of depression, anxiety or other psychiatric conditions.

Signs/symptoms
You may notice general hair loss, broken hairs, easily removable hair, thinning hair at the borders of any patch of hair loss or associated skin conditions, such as itching, scaling or inflammation. Any area of the body that has hair can be affected, including the scalp, beard, eyebrows and eyelashes.

Diagnosis
Your doctor will review your medical history and do a physical exam to determine the type of hair loss and its cause. The doctor may assess characteristics of your hair using hair samples, which can help determine what type of hair loss you have. Blood tests may help the doctor identify underlying disorders, and you may need tests to measure your thyroid, hormone or vitamin levels. In some cases, scalp biopsies (taking a sample of cells for further analysis) are recommended. Other tests will depend on your specific condition. In some cases, you may be referred to a dermatologist.

Treatment
Androgenetic alopecia
Standard treatment options for androgenetic alopecia include medication and surgery.

Medication:

Minoxidil (brand name Rogaine) is a topical solution (applied directly to the skin) that can stimulate hair growth.

Benefits of minoxidil: It has been shown to stabilize hair loss and improve new hair growth in some people. Minoxidil can be used by both men and women, and is available without a prescription.

Risks of minoxidil: It may take at least four months to see results. To maintain new hair growth, the medication must be taken indefinitely. Common reactions to minoxidil include burning, itching and redness at the application site.
Finasteride (Propecia) is taken orally. It works by interfering with the production of dihydrotestosterone, a hormone that's elevated in men who have male pattern baldness.

Benefits of finasteride: Finasteride may increase new hair growth and prevent further hair loss in some people.

Risks of finasteride: To maintain new hair growth, finasteride must be taken indefinitely. Side effects may include decreased sex drive and erectile dysfunction. Finasteride is not approved for use in women. Due to the potential harmful effects to a male fetus, crushed or broken tablets should not be handled by women who are or may be pregnant.
Spironolactone is an antiandrogen medication that may be used to treat androgenetic alopecia.

Benefits of spironolactone: If excess androgen (hormones such as testosterone) in the body is causing hair loss in women, spironolactone may lessen the hair loss.

Risks of spironolactone: This medication can only be used by women because of possible breast enlargement and other feminizing effects in men. Pregnant women should not take spironolactone, however, because of a concern for abnormal sexual development in the fetus.
Surgery:

Hair transplantation may be a treatment option for some people who have androgenetic alopecia. Hair plugs are taken from a portion of the scalp that has hair and moved to the area of baldness. The flap technique moves areas of hair rather than hair plugs.

Scalp reduction is a surgical technique that removes an area of balding scalp to lessen the appearance of baldness. Grafts or flaps may be done at the same time. The scalp may also be stretched, increasing the area where hair grows.

Benefits of surgery: Recent refinements in techniques have given more cosmetically pleasing results.

Risks of surgery: People who have very little hair may not be good candidates for surgical treatment. Scarring and infection are possible from surgery, and the transplanted hair may only last a few years.
Alopecia areata
Treatment is often determined by the extent of the hair loss and may include the use of medication or light therapy.

Medication:

Steroid injections or a topical application of steroids may be used to stimulate hair growth for people who have lost less than half of their hair. People who have lost more than half of their hair are often treated with a combination of medications, such as topical anthralin and minoxidil, topical steroids and minoxidil, or a specific topical allergen (any substance that stimulates an immune response or allergic reaction) to force follicle growth. Examples of topical allergens include dinitrochlorobenzene and squaric acid dibutyl ester. Oral steroids may be used alone or in combination with topical or injected steroids, but are usually reserved for extensive or rapidly spreading cases.

Benefits of steroids: Topical steroids may help stimulate new hair growth in mild to moderate cases, but injections may be more effective for more serious cases.

Risks of steroids: Steroid injections may be painful and need to be repeated every four to six weeks. Oral steroids are effective, but are rarely prescribed due to their side effects and need for long-term use (regrown hair may fall out when treatment stops).

Benefits of anthralin: It has been shown to stimulate hair growth and is considered safe.

Risks of anthralin: Scalp irritation may occur.

Benefits of minoxidil: It has been shown to stabilize hair loss and improve new hair growth in some people. Minoxidil can be used by both men and women, and is available without a prescription.

Risks of minoxidil: It may take at least four months to see results. To maintain new hair growth, the medication must be taken indefinitely. Common reactions to minoxidil include burning, itching and redness at the application site.

Benefits of topical allergens: Hair regrowth occurs in about 40 percent of people after six months of treatment.

Risks of topical allergens: These medications produce an itchy rash that may be uncomfortable. They do not permanently prevent further hair loss, and need to be continued to maintain hair regrowth. Topical allergens need to be managed by a dermatologist because of their potency.
Ultraviolet A (PUVA) therapy: Photochemotherapy can be received in your doctor's office. Also known as PUVA, it's a combination of the medication psoralen along with exposure to ultraviolet A (UVA) light. Psoralen, which is available in a pill or topical form, makes the body more sensitive to the light. It is thought PUVA acts on the immune system. Treatments are received two to three times a week, but may require long-term therapy.

Benefits of PUVA therapy: This may be an option if alopecia areata is resistant to other therapy.

Risks of PUVA therapy: This therapy can be effective, though long-term therapy may increase your risk of skin cancer. Hair loss may return when therapy is stopped.
For some people, hair transplantation may be a better treatment option for androgenic alopecia. Recent refinements in techniques have given more cosmetically pleasing results.

Alopecia areata
Standard treatment options for alopecia areata include direct injection of steroids or topical application of steroids, anthralin, minoxidil or a specific topical allergen (any substance that stimulates an immune response or allergic reaction). Controlled exposure to ultraviolet light may also be an option. Oral steroids are rarely prescribed due to their long-term side effects.

Telogen effluvium
Treatment is usually unnecessary because the hair grows back spontaneously. It

Traction alopecia
This type of hair loss can be treated by removing the underlying cause (such as a tight hairstyle or curlers). If scarring is extensive, new hair growth may be limited.

Alopecia cicatrisata
Treatment is typically aimed at the underlying cause. Because new hair growth may be limited, hair transplantation may be an option.

Trichotillomania
Treatment options typically include therapy and medications to treat underlying psychiatric disorders. Behavioral therapy, for example, can help the person address the tension that typically builds before pulling hair and learn healthier methods for releasing the tension.


Considerations
Coping with hair loss can be difficult, and contacting a support group may be beneficial. Learning different ways to style your hair to hide bald areas and wearing hairpieces or wigs are possible ways to cosmetically reduce the appearance of hair loss.

Pregnancy-specific information
The excessive hair loss you may notice two to three months after childbirth is related to the normal hormonal changes of pregnancy. It doesn't lead to baldness, but it's wise to follow a healthy postpartum diet and avoid pulling your hair tightly. Hair loss after childbirth can differ each time you have a baby.

Senior-specific information
Hair loss is often a normal part of the aging process. In fact, most older men and women have some degree of hair loss, although men often experience it to a greater extent than women. If you notice sudden changes in your hair or scalp, consult your doctor.

Prevention
Little can be done to prevent hereditary hair loss. To protect yourself from nonhereditary hair loss, lead a healthy lifestyle, eat healthfully, get regular medical checkups, and control treatable hair conditions. To avoid scalp infections, practice good personal hygiene and avoid sharing hair accessories such as hats, hair brushes or combs. To prevent traction alopecia, avoid tight hairstyles, ponytails, pigtails, braids and tight rollers.