Donating blood helps save lives and has positive benefits for donors, such as improving their emotional and physical health. People who donate blood may also experience side effects, such as minor bruising or feeling lightheaded.

Here, we look at the positive effects of donating blood and some temporary physical side effects that can occur. We also look at how to treat these side effects.

a woman doing a blood donation where she may experience side effects afterShare on Pinterest
A person can potentially save three lives through a single blood donation.
Image credit: Tim Boyle/Getty Images.

Donating blood helps supply hospitals and other settings with blood for those who need it during their treatment.

Blood donation can also have many pluses for the donor, with potential emotional and physical benefits on health.

Saving lives

According to the American Red Cross, someone in the United States will need blood every 2 seconds, and a single blood donation has the potential to save three lives.

Emotional and mental health

Helping others can have a positive effect on the people performing the good deed.

According to the Mental Health Foundation, a charity based in the United Kingdom, people who help others may experience:

  • more emotional well-being
  • less stress
  • greater sense of belonging and connection
  • less isolation
  • reduced or eliminated negative feelings

Physical health

People also get a free health checkup when they donate blood. Before being able to donate blood, the center staff will check that it is safe for donors to do so.

A test will check a person’s:

These checks may highlight any underlying conditions people are not aware of and help them seek treatment sooner.

Research has looked into the effects of blood donation on heart health.

A 2013 study consisting of 82 male and female participants found an improvement in cholesterol levels in blood donors.

Markers that suggest an increased risk of cardiovascular conditions were lower in regular blood donors compared with the nondonors, due to improved cholesterol levels. Researchers noted they need further evidence with larger studies to confirm these findings.

A larger scale 2019 study looked at the effects on heart health in 159,934 people who were regular blood donors.

The study found that regular, long-term blood donation had a protective effect against cardiovascular disease, although only in females.

Also, participants with a high frequency of donation had a lower chance of cardiovascular disease compared with low frequency donors.

Every 2 seconds, someone in the United States needs blood, but supplies are low due to COVID-19. To find out more about blood donation and how you can help, please visit our dedicated hub.

People may experience temporary physical side effects of donating blood.

Bruising and pain

People may experience some minor bruising due to blood under the surface of the skin. This is a normal reaction and should go away by itself within 1 week.

People may also experience some pain or tenderness at the site of the needle insertion, and possibly some minor swelling.

According to Bloodworks Northwest, a nonprofit organization, applying a compress can help to relieve pain and swelling.

Bloodworks suggest applying a cold compress four times a day for 20 minutes for the first 2 days.

Afterward, a person can apply a warm compress four times a day for 20 minutes.

A compress may ease any tenderness until the pain goes away. If people have severe or long lasting pain, they should contact their doctor.

Minor bleeding

People may experience minor bleeding from the needle site after donating blood. To help prevent this, they can leave their bandage on for a minimum of 4 hours after a donation.

If the site begins to bleed again, they can apply pressure for 2–5 minutes, and keep the bandage in place for a further 4 hours.

Fatigue and lightheadedness

People may feel fatigued or experience some dizziness, lightheadedness, or nausea after donating blood. This is because of the temporary lowering of blood pressure.

If a person feels faint, they can sit down and put their head between the knees so that it is lower than the heart. Lying down with the legs elevated can also help to prevent falling. If symptoms do not improve, people can contact their doctor.

To replenish fluid in the body, people need to drink water and other liquids before and after donating blood.

According to the American Red Cross, people can drink an additional 16 ounces (oz) of water before they donate blood, and an extra 8 oz of fluids afterward.

A person should avoid alcohol for 24 hours before and after donating.

People can continue to drink extra fluids for the following 3 days to replenish lost fluids in the body.

Healthful nutrition and eating iron-rich foods can help to replenish iron stores.

Examples of iron-rich foods include:

  • beef
  • turkey
  • spinach
  • shrimp
  • sweet potato
  • broccoli
  • tofu
  • beans
  • wheat products

Combining iron-rich foods with vitamin C helps the body absorb iron. Examples of vitamin C-rich foods include:

  • tomatoes
  • citrus fruits, such as oranges and lemons
  • red, orange, and yellow peppers

Regular donors may also find taking a multivitamin that contains iron helps to replenish iron stores.

People can take care to rest and avoid heavy lifting, strenuous exercise, or activity for the following 12 hours after donation. Resting helps the body to recover while it adjusts to the loss of blood.

People will rest at the donation center after they have given blood. This allows them to receive help straight away if they have any adverse side effects.

The center may provide a snack and drink for people to have afterward. Once people have rested and have no adverse symptoms, they can leave.

If someone experiences any long lasting or severe symptoms after giving blood, they can contact their doctor.

Learn more about how to recover after donating blood here.

Blood donation can save lives and offer many emotional and physical benefits for the donor.

Some people will experience minor side effects of donating blood, such as lightheadedness, bruising, or light bleeding. Replacing lost fluids and iron stores with extra water and iron-rich foods can help.

Keeping the bandage over the needle site for a few hours after the donation and avoiding strenuous activity can help minimize adverse effects and help the body recover more quickly.

If an individual experiences any severe symptoms, they should contact their doctor, or call 911 in an emergency.