Blood donation

While research continues on the development of a synthetic blood product, human donations are the only source of blood and its components. To donate blood, you can visit a blood bank or blood drive. Drives are often held at workplaces, schools and community centers. Because of periodic shortages, blood donation is extremely important.


Blood components and volume
Blood is made up of four components: platelets, plasma, red blood cells and white blood cells. Donated blood can be separated into these individual components to be delivered to those in need.
On average, men have about 10 to 12 pints of blood in their bodies. Women have about 8 to 9 pints. When you donate blood, you give roughly 1 pint. Your body replenishes the lost fluid within a few hours. The red blood cells are replaced within about eight weeks.


Blood types
There are four main blood types: A, B, AB and O. Each of these types are subdivided into an Rh type, either positive or negative. Rh signifies a protein found on the surface of red blood cells in most people. The most common blood type is O positive, followed by A positive, B positive, O negative, A negative, AB positive, B negative and AB negative. Other types of subcategories are identified in specific circumstances.
People who have type O blood are known as universal donors because anyone who needs blood can receive type O blood. People who have type AB blood are known as universal recipients because they can receive any type of blood.


Autologous transfusion
Donating your own blood ahead of time is known as autologous transfusion. Self-donation is typically done a few weeks before a scheduled surgery in case blood is needed during or after the procedure. If you wish, it may also be possible to receive donated blood from a family member or friend who shares your blood type. For details about self-donation, consult your doctor.

Blood testing
Before donated blood or any of its components are released from the blood bank, extensive screening for contamination takes place. Currently, donated blood is screened for each of the following elements:
antibodies and antigens to HIV, the virus that causes AIDS (Antibodies are compounds that help neutralize or destroy foreign subsances in the blood. Antigens are a type of foreign substance in the body that cause anitbodies to form. Two separate screening tests are done for HIV antibodies.)

antibodies to human T-cell lymphotropic virus, or HTLV (Types of this virus have been associated with types of leukemia, an uncontrolled, malignant growth of white blood cells in bone marrow.)

hepatitis B and C (infections of the liver with the hepatitis B or C virus)

current or past syphilis infection (a sexually transmitted disease often characterized by a sore on the genitals, tongue, lips or inside the body)

alanine aminotransferase (an enzyme involved in amino acid and carbohydrate metabolism that may indicate an infection of the liver in high levels)

nucleic acid amplification testing (NAT, a test recently approved by the U.S. Food and Drug Administration that allows for more sensitive testing for HIV and hepatitis C)
Thanks to thorough blood screening, the risk of transmitting viral infections (such as HIV and hepatitis) is very low. The risk of transmitting bacterial infections through platelet products (the portion of blood given to help with blood clotting) is higher than the risk of transmitting viruses through blood products, but currently there's no effective method to screen donor blood for these infections. Careful questioning of donors and a brief physical exam are used to spot symptoms of a bacterial illness.

Researchers are currently developing additional tests for screening blood. For example, a process for treating donor blood called pathogen inactivation may destroy the ability of bacteria and viruses to cause an infection. Remember, there's no risk of developing an infectious disease when you donate blood -- and you could be saving lives.


What to expect when donating blood
When you arrive at the blood drive or donation center, you may be asked for proof of identification. A staff member will ask questions about your medical history to determine your eligibility to donate blood. During a brief physical, a staff member will take your temperature and measure your pulse, blood pressure and weight. Your finger will be pricked for a drop of blood to check your hemoglobin level (a protein in the red blood cells that contains iron).
When you're ready to donate blood, the part of your arm where the blood will be drawn will be cleaned with an antiseptic. Then, you'll feel a needle stick as a member of the medical staff places the needle in your arm. The blood will be collected into a sterile bag that contains an anticoagulant/preservative solution. You may be asked to form your hand into a fist and squeeze repeatedly to help the blood flow into the bag. The needle will then be removed and a bandage will be applied. Collecting a pint of blood typically takes less than 10 minutes. Afterward, you'll be asked to rest. Refreshments are often available. The entire process usually takes about 20 minutes.

In the first few hours after donating blood, drink plenty of fluids and eat a hearty meal. You may resume normal activity after 30 minutes, but refrain from strenuous activity the rest of the day. The bandage may be removed after 24 hours. Contact the blood donation center if you have any concerns after the donation.

All donated blood is typed and labeled for future use. Red blood cells can be stored for 42 days. Again, the blood goes through extensive screening tests before use. As a final precaution, a small amount of the donor's blood and the recipient's blood are mixed together in the lab before transfusion to ensure compatibility.

Because donated blood goes through several tests, you may be notified about a finding in your blood within a few weeks after you donate. If this happens, don't panic. Simply follow the instructions in the notice and provide the information to your health care provider. If you identify a condition that may make your blood unsuitable for donation after you donate blood, notify the blood donation center. They'll make a determination about safe use of your donated blood.


Platelet donation
Today it's possible to donate single blood components, such as platelets, through a process called apheresis. Platelets help in the clotting process and are often needed by people who have leukemia and other types of cancer. Donation through apheresis allows for more platelets to be collected. For example, one apheresis platelet donation contains about six times more platelets than one whole blood donation.
The process for platelet donation is similar to regular blood donation, but takes longer -- up to two hours. During the donation, an apheresis instrument separates the blood into its components, retains the platelets and returns the remainder of the blood to you.


General guidelines for blood donation
To help ensure the safety and health of both donors and recipients, you must wait at least 56 days between blood donations. Platelet donors may donate more frequently -- sometimes as soon as 48 hours between donations -- because platelets are quickly replenished by the body. You must be age 17 or older, in good general health and weigh at least 110 pounds.
If you immigrated from a country known to have malaria, you must live in the United States for three years with no symptoms of malaria before donating blood. If you've traveled to an area known to have malaria, you must wait one year with no symptoms before donating blood (whether or not you took antimalarial medications).

You may also be able to donate blood if:

You had anemia (a condition marked by a decreased number of red blood cells or hemoglobin, a protein in red blood cells that contains iron), but the condition has been corrected.

You had a flu shot more than 24 hours before the donation and have no flu-like symptoms.

You received the hepatitis B vaccine for preventive purposes more than seven days ago.

You had a blood or plasma transfusion more than one year ago.

You have herpes but the condition isn't in an active stage.
Other guidelines may vary at separate regional blood donation sites. Check with your doctor and the donation center regarding specific guidelines, including the following:

If you've been taking oral antibiotics, you may need to be off the medication from 48 hours to seven days before donation, depending on the reason for the antibiotics. Antibiotics taken for acne don't disqualify you from donating blood.

If you have diabetes, you may be able to donate blood if your condition is controlled through diet or oral medication. Some sites also allow donations if you take insulin if you've been taking it for more than two weeks and have never used beef insulin made in the United Kingdom.

If you had a heart attack more than six months ago, you may be able to donate blood if you're free of symptoms, have no restrictions on physical activities, and aren't taking medication for heart disease, other than aspirin. At some sites, people who have heart failure or heart disease aren't allowed to donate blood.

If you had a common type of skin cancer, you may be able to donate blood if the cancer has been surgically removed and is completely healed. You may also be able to donate blood if you had another type of cancer that didn't require chemotherapy and hasn't recurred in five years. At some sites, people who have cancers other than cured skin cancer or cervical cancer aren't allowed to donate blood.

Who shouldn't donate blood
Prior to 2002, anyone who had been in the United Kingdom (UK) for a total of three months or more from 1980 to 1996 or received a blood transfusion while in the UK since 1980 wasn't allowed to donate blood in the United States. (This guideline was meant to help prevent the possible spread of variant Creutzfeldt-Jakob disease, a fatal disease of the central nervous system thought to be related to eating contaminated beef products). Since 2002, however, the U.S. Food and Drug Administration has instituted stricter bans.
Today, blood donations aren't accepted from anyone who has visited or lived in Europe for a total of five or more years between 1980 and today. The American Red Cross recently changed its rules as well. They won't accept blood donations from anyone who has been in the UK for three or more months since 1980, or who has lived in any country in Europe for more than six months since 1980. Check with your donation center for additional details.

Additional people who shouldn't donate blood include anyone who:

has hepatitis (inflammation of the liver)

has high blood pressure that's not medically controlled or tops 180/100 mm Hg (millimeters of mercury, the standard measurement for blood pressure)

is at risk for exposure to HIV or AIDS, has symptoms of HIV or AIDS, or is known to be HIV-positive or have AIDS

injects recreational drugs

has anemia

has kidney, lung, heart or liver failure

takes Tegison for psoriasis (a chronic skin disease marked by patches of raised, red bumps covered with white, flaking scales on the scalp, knees, elbows or buttocks)

has hemophilia (an incurable, inherited blood disease that affects a blood clotting factor) and is taking clotting factor concentrates

had a body part pierced, electrolysis or acupuncture within the past year (unless disposable needles were used and Centers for Disease Control and Prevention recommendations for needle disposal were followed)

had a tattoo or permanent makeup applied within the past year

had major surgery in the past six months (For a recent surgery, some centers accept donations when you're released from medical care.)

Waiting periods for blood donation
Waiting periods may be imposed for any of the following conditions or treatments.
Cough, sore throat or common cold: Wait until you're free of symptoms.

Mononucleosis: Wait until your doctor gives you the OK.

Alcohol intoxication: Wait until you're sober.

Hepatitis exposure: Depends on the type of hepatitis exposure. You're often excluded until your doctor determines it's safe for you to donate blood. If you had an accidental exposure such as a needle puncture and then received the hepatitis B vaccine, the waiting period is one year.

Severe acute respiratory syndrome (SARS): If you've traveled to an area with a large number of cases (mainland China and Hong Kong; Hanoi, Vietnam; or Singapore) but show no symptoms of SARS, you must wait 14 days after returning to donate blood. People who've had SARS can't donate blood until 28 days after symptoms have resolved and treatment is complete.

West Nile virus: Wait 28 days from the time symptoms appear or until you've been without symptoms for 14 days.

Syphilis or gonorrhea (sexually transmitted diseases): Wait one year after the infection is cleared up.

Oral surgery or tooth extraction: Wait 72 hours after the procedure. You'll also need to wait if there's any possible infection.

Immunizations: Wait two weeks after a measles, yellow fever, mumps or oral polio vaccination. Wait four weeks after a rubella (German measles), MMR (measles, mumps, rubella) or chickenpox vaccination. Make sure you're free of any postvaccination symptoms.

Tuberculosis skin test: Wait 48 hours after the test.

Medications: Certain drugs may warrant various waiting periods.

Previous donations: Wait 48 hours after you've donated blood for apheresis (the removal of certain components from your blood). Wait 56 days after you've donated a pint of whole blood.

Pregnancy-specific information
Pregnant women aren't allowed to donate blood. Most women are eligible to donate six weeks after a full-term delivery, C-section, or third trimester abortion or miscarriage.

Senior-specific information
Generally, there's no upper age limit for donating blood. Growing older puts you at increased risk of chronic health problems, however, which may affect your eligibility to donate blood.