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Donating Blood

Topic Overview

What is blood donation?

Blood donation is giving some of your blood so that it can be used to help someone else. Donated blood helps people who have lost blood in an accident or who have an illness such as cancer, anemia, sickle cell disease, or hemophilia.

Donated blood includes red blood cells and the other things that make up the blood, such as platelets and plasma. Blood that contains all the parts is called whole blood.

You can donate blood at American Red Cross clinics or other clinics or blood banks. You may be able to donate during blood drives at your workplace.

About 1 pint (480 mL) of blood is taken when you donate. It takes about 10 minutes. The whole process—including answering questions and having a short exam—takes up to an hour.

Donated blood is tested to make sure that it is safe to use. It's also checked for its type. This makes sure that the person who needs blood gets the right type.

Who can donate blood?

To donate blood, you must:

  • Be at least 17 years old. (In some states, you can donate if you are 16 years old and get permission from a parent.)
  • Weigh at least 110 lb (50 kg).
  • Be in good health.

Some people can't donate because of health or other issues. For example, you may not be able to donate if:

  • You donated blood in the past 56 days.
  • You don't have enough iron in your blood. Before you donate, you will have a test to check your iron level.
  • You are pregnant.
  • You have traveled to certain countries.
  • Your blood pressure is too high. Your blood pressure will be checked before you donate.
  • You take certain medicines.
  • You have certain health problems.

Having a long-term illness, such as diabetes, doesn't mean you can't donate. You may be able to give blood if your health problem is under control. But you shouldn't donate blood if you feel like you're getting a cold or the flu.

Before you donate, a health professional will ask about your current and past health to make sure that you can donate. Some of these questions are very personal, so you will be asked them in private. You will be asked these questions every time you give blood, because the list of who can give blood may change, or your health may change.

What should you do BEFORE you give blood?


  • Drink plenty of fluids.
  • Get plenty of sleep the night before.

What happens when you donate blood?






What should you do AFTER you give blood?



In the hours after you give blood, make sure to:

  • Drink plenty of fluids to help replace the lost fluid.
  • Limit your physical activity for several hours.



What are the risks of donating blood?

There are no health risks in giving blood. You CANNOT get AIDS or other diseases from donating blood. The needle and bag used to collect blood are sterile and prepackaged. A new package is used every time.

You may have a small bruise on your arm. In rare cases, a person's arm may bleed after the bandage is taken off. If this happens, raise your arm and put pressure on the needle site for several minutes.

What tests are done on donated blood?

After donation, your blood is tested for certain diseases, such as hepatitis B and C, HIV, West Nile virus, and HTLV-III virus. Donated blood must pass all of these tests. If any disease is detected, the blood is thrown away and the donor is notified.

Other Places To Get Help


American Red Cross
Web Address: or (Spanish)

Related Information


Other Works Consulted



By Healthwise Staff
Primary Medical Reviewer E. Gregory Thompson, MD - Internal Medicine
Specialist Medical Reviewer Brian Leber, MDCM, FRCPC - Hematology
Last Revised October 27, 2011



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