Houston Methodist. Leading Medicine.
Houston Methodist. Leading Medicine

Blood Donor Screening Criteria

Blood Donor Screening Criteria

Most blood donors are volunteers. However sometimes a patient may want to donate blood prior to undergoing surgery, so that his/her blood is available in case a transfusion becomes necessary. Patients donating for themselves are exempt from many of the following requirements. Feel free to check with our staff for details.

To ensure the safety of the blood donation process and available blood supply, volunteer blood donors must meet specific criteria:

  • Age - Donor must be seventeen years of age or older. There is no upper age limit.
    (Some states permit persons younger than 17 years to donate blood with parental consent.)
  • Weight - Donor must weight 110 pounds (50 kg) or more.
  • Health - Donor must be in general good health. Some minor health problems, such as cold or flu, may temporarily disqualify donors. Other significant medical histories, i.e. major surgery, blood transfusion, etc. excludes potential donors for up to one year. Some diseases, such as malaria will exclude donors for up to three years. More serious health issues, such as a history of heart disease, cancer, hepatitis, organ failure, HIV (exposure or high risk), intravenous drug abuse, etc. usually disqualify blood donation permanently. To establish that a potential donor can give blood safely, a mini physical is given by a member of our staff. This includes a general review of the medical history, blood pressure check, pulse rate check, temperature check and hemoglobin level check. If you are taking any medications, especially prescription medications, you will be asked which ones and the reason(s) for which they are taken. Examination is given prior to donation.
  • Travel History - Travel and or a prolonged stay in some foreign countries can result in temporary or permanent disqualification. This is done according to AABB (American Association of Blood Bank) and FDA (Federal Drug Administration) guidelines. The issues involved may be a potential exposure to malaria, mad cow disease, etc. Please check with our staff for more details.

It is recommended that prospective donors eat prior to giving blood. After donation normal daily activities may resume. We do recommend that donors avoid lifting heavy weights or performing strenuous exercise for several hours.

You may donate blood platelets and plasma 24 times a year up to 12 liters per year.

Standard Tests:

A set of standard tests are performed in the laboratory once blood is donated, including, but not limited to the following:

  • Typing: ABO group (blood type)
  • Rh typing (positive or negative antigen)
  • Screening for any unexpected red blood cell antibodies that may cause problems in the recipient
  • Screening for current or past infections
    including the following:
    • hepatitis viruses B and C
    • human immunodeficiency virus (HIV)
    • human T-lymphotrophic viruses (HTLV)
      I and II
    • syphilis
  • Irradiation to blood cells is performed to disable any T-lymphocytes present in the donated blood. (T-lymphocytes can cause a reaction when transfused, but can also cause what is called 'graft-versus-host' problems with repeated exposure to foreign cells.)
  • 'Leukocyte reduced blood' has been filtered to remove the white blood cells which contain antibodies that can cause fevers in the recipient of the transfusion. (These antibodies, with repeated transfusions, may also increase a recipient’s risk of reactions to subsequent transfusions.)

What are the components of blood?

While blood, or one of its components, may be transferred, each component serves many functions:

  • Red blood cells - carry oxygen to the tissues in the body and are commonly used in the treatment of anemia.
  • Platelets - help the blood to clot and are used in the treatment of leukemia and other
    forms of cancer.
  • White blood cells - help to fight infection and aid in the immune process.
  • Plasma - the watery, liquid part of the blood in which the red blood cells, the white blood cells, and platelets are suspended. Plasma is needed to carry the many parts of the blood through the bloodstream. Plasma serves many functions, including the following:
    • Helps to maintain blood pressure
    • Provides proteins for blood clotting
    • Balances the levels of sodium and potassium
  • Cryoprecipitate AHF - a portion of the plasma that contains clotting factors that
    help to control bleeding.

Albumin, immune globulins, and clotting factor concentrates may also be separated and processed for transfusions.