Blood donation

Blood Donation

After blood draw for donation or treatment: Overview

You have just had some blood removed. This procedure is called phlebotomy (say "fleh-BAW-tuh-mee").

People have their blood taken (drawn) for several reasons. You may have just donated blood so that it can be used to help someone else. Or you may have had blood removed to treat a medical condition, such as hemochromatosis or polycythemia. These take more blood than the sample that is needed for simple lab tests. For donation, about a pint of blood is drawn. If it's drawn for treatment, then more or less than a pint may be taken.

The puncture wound caused by the poke from the needle for giving blood usually heals without trouble. Most people feel fine after they give blood. But there are some simple things you can do to take care of yourself before you go home.

  • Right after you give blood, you may be asked to sit for a while and have some water or juice and a snack.
  • When you leave, get up slowly to make sure that you're not lightheaded. You may want to have a family member or friend take you home.

How is blood donation done?

You will fill out some forms and answer questions about your health.

A health professional will measure your temperature, pulse, and blood pressure. They also will use a finger-stick test to make sure that you have enough hemoglobin in your blood.

The health professional will clean the arm you will use to give blood. Then they will put a needle into a vein on the inside of your elbow. The needle is attached to a bag to collect the blood. You will probably feel a quick pinch when the needle goes in.

You may be given a soft ball or another object to squeeze every few seconds to help the blood flow.

When the bag is full, the health professional will take out the needle. You will get a bandage wrapped around your arm to stop any bleeding.

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). If you are under 18 years old, you may need to meet a certain height and weight measurement.
  • 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 recently donated blood or a blood product. The length of time you must wait between donations depends on the product you are donating, such as whole blood or platelets.
  • You don't have enough hemoglobin in your blood. Before you donate, you will have a test to check your hemoglobin level.
  • You are pregnant.
  • You have traveled to certain countries.
  • Your blood pressure is too high or too low. Your blood pressure will be checked before you donate.
  • You take certain medicines.
  • You have certain health problems, such as HIV.
  • You had a recent needlestick or got a tattoo or piercing.

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.

Your body will replace the lost fluid in 24 hours. (It takes a few weeks to replace red blood cells.) You will have to wait 56 days before you can give whole blood again.

Blood draw for donation or treatment: When to call

Call your doctor now or seek immediate medical care if:

  • You are dizzy or lightheaded or feel like you may faint.
  • You have signs of infection, such as:
    • Increased pain, swelling, warmth, or redness.
    • Red streaks leading from the area.
    • Pus draining from the area.
    • A fever.

Watch closely for changes in your health, and be sure to contact your doctor if you have any problems.

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The content above contains general health information provided by Healthwise, Incorporated, and reviewed by its medical experts. This content should not replace the advice of your healthcare provider. Not all treatments or services described are offered as services by us. For recommended treatments, please consult your healthcare provider.