By Mayo Clinic Staff
Blood donation is a voluntary procedure. 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 are several types of blood donation:
- Whole blood. This is the most common type of blood donation, during which approximately a pint of whole blood is donated. The blood is then separated into its components — red cells, plasma, platelets.
- Platelets. This type of donation uses a process called apheresis. During apheresis, the donor is hooked up to a machine that collects the platelets and some of the plasma, and then returns the rest of the blood to the donor.
- Plasma. Plasma may be collected simultaneously with a platelet donation, or it may be collected without collecting platelets during an apheresis donation.
- Double red cells. Double red cell donation is also done using apheresis. In this case, only the red cells are collected.
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.
To be eligible to donate whole blood, platelets or plasma, you must be:
- In good health.
- At least 17 years old — the minimum age varies by state, with some states allowing 16-year-olds to donate with parent permission; there's no upper age limit.
- At least 110 pounds.
- Able to pass the physical and health history assessments.
The eligibility requirements are slightly different for double red cell donation. Check with your local donor center for specifics.
Get plenty of sleep the night before you plan to donate. Eat a healthy meal before your donation. Avoid fatty foods, such as hamburgers, 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.
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 physician, such as illegal injection drugs or steroids not prescribed by a physician
- Men who have had sexual contact with other men since 1977
- Anyone who has ever received clotting factor concentrates
- Anyone with a positive test for HIV (AIDS virus)
- Men and women who have engaged in sex for money or drugs
- Anyone who has had hepatitis after his or her 11th birthday
- Anyone who has had babesiosis or Chagas' disease
- Anyone who has taken etretinate (Tegison) for psoriasis
- Anyone who has risk factors for 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 examination, 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 is becoming increasingly common and is known as 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. However, it takes longer than standard blood donation — typically one 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 for at least four to five hours.
- If you have bleeding after removing the bandage, put pressure on the site and raise your arm for three to five minutes.
- 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. Avoid taking aspirin or ibuprofen (Advil, Motrin, others).
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. So you're either Rh positive or Rh negative, meaning you carry the antigen or you don't. 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 blood bank notifies you, and your blood is discarded and not used.
May 30, 2014
- Blood FAQ. AABB. http://www.aabb.org/resources/bct/Pages/bloodfaq.aspx. Accessed March 25, 2014.
- Eligibility requirements. American Red Cross. http://www.redcrossblood.org/donating-blood/eligibility-requirements. Accessed March 25, 2014.
- FAQs about donating blood. American Red Cross. http://www.redcrossblood.org/donating-blood/donation-faqs. Accessed March 25, 2014.
- Tips for a good donation experience. American Red Cross. http://www.redcrossblood.org/donating-blood/tips-successful-donation. Accessed March 25, 2014.
- Winters JL (expert opinion). Mayo Clinic, Rochester, Minn. March 27, 2014.
- Kleinman S. Procedures used for blood donor screening: Protection of potential blood donors and recipients. http://www.uptodate.com/home. Accessed March 25, 2014.
- Kleinman S. Blood donor medical history. http://www.uptodate.com/home. Accessed March 25, 2014.