Medically reviewed on December 27, 2017
Blood donation is a voluntary procedure that can help save the lives of others. There are several types of blood donation, which help meet different medical needs.
Whole blood donation
This is the most common type of blood donation, during which you donate about a pint of whole blood. The blood is then separated into its components — red cells, plasma, platelets.
During apheresis, you are hooked up to a machine that can collect and separate blood components, including red cells, plasma, platelets, and return unused components back to the donor.
Platelet donation (plateletpheresis) collects only platelets — the cells that help stop bleeding by clumping and forming plugs (clotting) in blood vessels.
Donated platelets are commonly given to people with leukemia, people receiving chemotherapy and babies with severe infections.
Double red cell donation allows you to donate twice the amount of red blood cells than you normally would during a whole blood donation. Red blood cells deliver oxygen to the entire body.
People with a medical need for only red blood cells include those with severe blood loss, such as after an injury or accident, and those who have anemia with serious symptoms
Plasma donation (plasmapheresis) collects the liquid portion of the blood (plasma). Plasma helps blood clot and contains proteins and other substances, such as electrolytes, that help the body function normally.
Plasma is commonly given to people with liver conditions, burns and severe bacterial infections in their blood.
Why it's done
You agree to have blood drawn so that it can be given to someone who needs a blood transfusion.
Millions of people need blood transfusions each year. Some may need blood during surgery. Others depend on it after an accident or because they have a disease that requires blood components. Blood donation makes all of this possible. There is no substitute for human blood — all transfusions use blood from a donor.
Blood donation is safe. New, sterile disposable equipment is used for each donor, so there's no risk of contracting a bloodborne infection by donating blood.
If you're a healthy adult, you can usually donate a pint of blood without endangering your health. Within 24 hours of a blood donation, your body replaces the lost fluids. And after several weeks, your body replaces the lost red blood cells.
How you prepare
To be eligible to donate whole blood, plasma or platelets, you must be:
- In good health.
- At least 16 or 17 years old, depending on the law in your state. Some states allow legal minors to donate with parent permission. While there's no legal upper age limit, policies may vary between individual donor centers.
- At least 110 pounds.
- Able to pass the physical and health-history assessments.
Eligibility requirements differ slightly between different types of blood donation, and from center to center. Check with your local donor center for specifics.
Food and medications
Before your blood donation:
- Get plenty of sleep the night before you plan to donate.
- Eat a healthy meal before your donation.
- Avoid fatty foods, such as hamburgers, french fries or ice cream before donating. Tests for infections done on all donated blood can be affected by fats that appear in your blood for several hours after eating fatty foods.
- Drink an extra 16 ounces (473 milliliters) of water and other fluids before the donation.
- If you are a platelet donor, remember that you must not take aspirin for two days prior to donating. Otherwise, you can take your normal medications as prescribed.
What you can expect
Before the procedure
Before you can donate blood, you will be asked to fill out a confidential medical history that includes direct questions about behaviors known to carry a higher risk of bloodborne infections — infections that are transmitted through the blood. All of the information from this evaluation is kept strictly confidential.
Because of the risk of bloodborne infections, not everyone can donate blood. The following high-risk groups are not eligible to donate blood:
- Anyone who has ever used injection drugs not prescribed by a doctor, such as illegal injection drugs or steroids not prescribed by a doctor
- Men who have had sexual contact with other men in the past 12 months
- Anyone who has a congenital coagulation factor deficiency
- Anyone with a positive test for HIV
- Men and women who have engaged in sex for money or drugs
- Anyone who, in the past 12 months, has had close contact with — lived with or had sexual contact with — a person who has viral hepatitis
- Anyone who has had babesiosis, a rare and severe tick-borne disease, or the parasitic infection Chagas' disease
- Anyone who has taken etretinate (Tegison) for psoriasis
- Anyone who has risk factors for the degenerative brain disorder Creutzfeldt-Jakob disease (CJD) or who has a blood relative with CJD
- Anyone who spent three months or more in the United Kingdom from 1980 through 1996
- Anyone who received a blood transfusion in the United Kingdom or France from 1980 to the present
- Anyone who has spent five years in Europe from 1980 to the present
You will also have a brief physical exam, which includes checking your blood pressure, pulse and temperature. A small sample of blood is taken from a finger prick and is used to check the oxygen-carrying component of your blood (hemoglobin level). If your hemoglobin concentration is normal and you've met all the other screening requirements, you can donate blood.
During the procedure
You lie or sit in a reclining chair with your arm extended on an armrest. A blood pressure cuff or tourniquet is placed around your upper arm to fill your veins with more blood. This makes the veins easier to see and easier to insert the needle into, and also helps fill the blood bag more quickly. Then the skin on the inside of your elbow is cleaned.
A new, sterile needle is inserted into a vein in your arm. This needle is attached to a thin, plastic tube and a blood bag. Once the needle is in place, you tighten your fist several times to help the blood flow from the vein. Blood initially is collected into tubes for testing. When these have been collected, blood is allowed to fill the bag, about a pint. The needle is usually in place about 10 minutes. When complete, the needle is removed, a small bandage is placed on the needle site and a dressing is wrapped around your arm.
Another method of donating blood becoming increasingly common is apheresis. During apheresis, blood is drawn from one arm and pumped through a machine that separates out a specific component, such as platelets. The rest of the blood is then returned through a vein in your other arm. This process allows more of a single component to be collected. It takes longer than standard blood donation — typically up to two hours.
After the procedure
After donating you sit in an observation area, where you rest and eat a light snack. After 15 minutes, you can leave. After your blood donation:
- Drink extra fluids for the next day or two.
- Avoid strenuous physical activity or heavy lifting for the next five hours.
- If you feel lightheaded, lie down with your feet up until the feeling passes.
- Keep the bandage on your arm and dry for five hours.
- If you have bleeding after removing the bandage, put pressure on the site and raise your arm until the bleeding stops.
- If bleeding or bruising occurs under the skin, apply a cold pack to the area periodically during the first 24 hours.
- If your arm is sore, take a pain reliever such as acetaminophen (Tylenol, others). Avoid taking aspirin or ibuprofen (Advil, Motrin IB, others) for the first 24 to 48 hours after donation.
Contact the blood donor center or your doctor if you forgot to report any important health information before you donated or if you had any problems or needed medical care after giving blood.
You should also call the center if you:
- Continue to feel nauseated, lightheaded or dizzy after resting, eating and drinking.
- Notice a raised bump, continued bleeding or pain at the needle-stick site when you remove the bandage.
- Feel pain or tingling down your arm, into your fingers.
- Become ill with signs and symptoms of a cold or flu, such as fever, headache or sore throat, within four days after your blood donation. Bacterial infections can be transmitted by your blood to another person via transfusion, so it's important to let the blood donor center know if you become ill so that your blood won't be used.
Your blood will be tested to determine your blood type — classified as A, B, AB or O — and your Rh factor. The Rh factor refers to the presence or absence of a specific antigen — a substance capable of stimulating an immune response — in the blood. You'll be classified as Rh positive or Rh negative, meaning you do or don't carry the antigen. This information is important because your blood type and Rh factor must be compatible with the blood type and Rh factor of the person receiving your blood.
Your blood will also be tested for bloodborne diseases, such as hepatitis, HIV and syphilis. If these tests are negative, the blood is distributed for use in hospitals and clinics. If any of these tests are positive, the donor center notifies you, and your blood is discarded.