Measles Information

Bags of blood marked "B Rh Positive," "B Rh Negative," and "AB Rh Positive" in a rack.
Bags of blood marked "B Rh Positive," "B Rh Negative," and "AB Rh Positive" in a rack.

What Does Your Blood Type Mean for Your Health?

What Studies Suggest

There are eight main blood types:

  • Type A-positive
  • Type A-negative
  • Type B-positive
  • Type B-negative
  • Type O-positive
  • Type O-negative
  • Type AB-positive  
  • Type AB-negative

What determines if your blood is positive or negative is the Rhesus (Rh) factor, which is an inherited protein in red blood cells. If your blood cells have the Rh protein, then you have a positive blood type. If there is no Rh protein in your blood cells, you have a negative blood type.

Knowing your blood type can be crucial in a medical emergency, but it can also offer some interesting insight into your health, according to Glenn E. Ramsey, MD.

Dr. Ramsey explains how your blood type may affect your health.

Heart Disease

Of the eight main blood types, people with Type O have the lowest risk for heart attacks and blood clots in the legs and lungs. This may be because people with other blood types have higher levels of certain clotting factors, which are proteins that cause blood to coagulate (solidify). A heart-healthy lifestyle is particularly important for people with Type A, B and AB blood.


Studies have found that people with Type A or Type AB are at higher risk for gastric cancer. Additionally, if you have Type A, Type B or Type AB blood, you may have a higher risk for pancreatic cancer.


Research suggests that people with:

  • Type A blood may be at higher risk for COVID-19 infection
  • Type O blood may be somewhat less likely to test positive for COVID-19 and have less severe disease than people with other blood types
  • Negative blood types may be also slightly less prone to COVID-19 infection

More data is still needed to confirm these hypotheses but the studies help physician-scientists learn more about how blood types affect health.

Knowing your blood type is one more way to better understand and manage your health. While your blood type is genetic and cannot be altered, making healthy choices can help you reduce risks to your health.