10 Myths About Donating Blood, Debunked

According to the American Red Cross, someone in the U.S. requires blood every two seconds—but just 3 percent of eligible adults donate blood in a given year. Each day, U.S. hospitals and trauma centers require about 29,000 units of red blood cells, 5000 units of platelets and 6500 units of plasma for transfusion during surgery, chemotherapy, or treatments for chronic conditions. If you’ve ever considered donating blood but haven’t gone through with it, read on as we debunk some common myths about this live-saving action.

1. Myth: Giving blood might make you sick.

If you’re healthy before donating blood, you won't get sick from donating blood. Plasma—the liquid part of your blood—will regenerate its normal volume within 48 hours, and your red blood cells will return to their normal volume in one to two months. (That’s why the Red Cross tells donors to wait a minimum of eight weeks between donations of whole blood.) You may feel a bit lightheaded or experience temporary pain in your arm where the needle went in, but those symptoms will resolve after a day or so. The Red Cross recommends drinking liquids and resting following your donation.

2. Myth: It takes too long.

When asked why they haven’t donated blood, 15 percent of people claim they’re too busy. But blood centers say that whole blood donations take just about an hour. Donating only platelets, red blood cells, or plasma, called an apheresis blood donation, can take about twice as long.

The appointment begins with a series of questions about your health and travel history. A technician will check your pulse, temperature, blood pressure, and hemoglobin level. Then, your time on the table takes roughly eight to 10 minutes, which is sufficient for drawing one pint (or “unit”) of whole blood—and that one unit can save three lives. Following the donation, you can rest for 10 to 15 minutes and enjoy juice and cookies before resuming your daily activities.

3. Myth: People with tattoos or piercings can’t donate blood.

Blood centers recommend that you wait three months after getting a new piercing or tattoo before you donate blood, especially if you got your new ink or piercing in a state where such facilities are not regulated or do their work with reusable instruments.

4. Myth: It hurts.

Other than a slight twinge when the needle goes in, you won’t suffer much discomfort. There’s no pain when blood is drawn or when the needle is removed. Your arm might be a bit sore and you could have slight bruising, but these effects last but a few days.

5. Myth: Blood centers only need donations of rare blood types.

Donations of all blood types are appreciated, no matter how commonly your type may occur in the population. Some blood banks post weekly urgent requests for specific blood types depending on their current shortages.

There are eight known blood types: A+, A-, B+, B-, O+, O-, AB+, and AB-. Among the U.S. population, O+ and A+ are the two most common by far:

People with the O- blood type are known as “universal donors” because their blood can be used in any transfusion, regardless of the recipient’s blood type. According to the Red Cross, O type blood is always in demand because O+ is the most common type and O- can be used for all procedures.

6. Myth: You can’t donate if you take medications or have a chronic illness.

Only a few conditions put you on the lifetime “cannot donate” list, such as having HIV, hepatitis B or C, or sickle cell disease. There are prescribed waiting periods if you’ve had cancer, a cold or flu, surgery, a recent pregnancy, COVID-19, or some vaccinations. If you’re taking medications for a chronic condition like hypertension or diabetes that is under control, you should be able to donate. Aspirin, antibiotics, and other drugs have their own rules and regulations. The American Red Cross’s FAQ lays out some specifics.

7. Myth: Donated blood can be stored forever.

Red blood cells separated from the other blood components will last up to 42 days if they’re refrigerated properly. Platelets are stored at room temperature for up to five days in machines called agitators, which continuously jiggle the platelets to keep them oxygenated. Plasma can be frozen for up to a year. When any of these components expire, they’re thrown away.

8. Myth: There’s an age limit for giving blood.

There’s no age limit—you can be 100 years old and still donate—but you do have to be 17 years of age or older to donate without a parent’s or guardian’s consent. If you’re healthy, older age doesn’t matter.

9. Myth: High blood pressure precludes you from giving blood.

“Helping others” is the main reason people give blood, but it comes with a bonus physical benefit: If you have high blood pressure, giving blood can lower it (since it temporarily reduces the total volume of blood going through your circulatory system). When the technician takes your blood pressure during the pre-donation health screening, your systolic BP (the top number) must be lower than 180 and your diastolic BP (the bottom number) must be lower than 100. Taking medication for hypertension will not disqualify you.

10. Myth: Men who have had sex with men can never donate blood.

Beginning in 1983, due to the emerging HIV/AIDS epidemic, U.S. public health officials implemented rules restricting sexually active gay and bisexual men from donating blood to protect the nation’s blood supply. In 1986, the FDA issued guidance prohibiting any man who had had sex with a man after 1977 from ever donating blood, and the essence of the rule has stayed in place [PDF] despite many advances in blood screening. Advocates have argued that, with the safety of the blood supply secured, there is no need to continue excluding men who have sex with men from giving blood.

In May 2023, the FDA finally updated its guidelines [PDF] to allow gay and bisexual men to give blood. The rules now call for blood bank officials to ask each potential donor about his or her history of high-risk behavior—such as engaging in nonprescription injection drug use or having sex with someone who does—within the prior three months. The guidance is meant to more accurately screen an individual’s actual risk.