Possible Connection: Stroke & Blood Type

By Nadine Salmon, BSN, IBCLC, Clinical Content Specialist AMN Healthcare

Did you know that blood type may affect stroke risk? There’s growing evidence that people with AB type, and women with B type blood, are at increased risk of developing a stroke than individuals with O type blood. Although an absolute link has not yet been conclusively established, this finding is consistent with other research findings that blood types A, B and AB are associated with an increased risk of thrombi and heart attacks. Blood type O has also been tied to an increased risk of bleeding, which implies a lower risk of clot formation (American Stroke Association, 2011).

Findings from a recent study in Boston were presented at the American Heart Association conference in November. The study found that men and women with type AB blood had a 29%increased risk of ischemic stroke, compared to those with type O. In addition, women, with B type blood had a 17% greater risk compared to women with O type (American Stroke Association, 2011). It appears that certain blood types may make red cells more likely to clump together and stick to the lining of blood vessels, setting the stage for a blood clot (Manson, 2011 in the American Stroke Association, 2011).

Blood type cannot be modified or adjusted, but knowing the risk may encourage some individuals to more closely examine modifiable risk factors and take action to decrease overall risk for stroke. Modifiable risk factors for stroke include smoking, alcohol abuse and immobility. Educating the public on the importance of following a healthy lifestyle can greatly reduce these modifiable risk factors, and blood type may be used as a stimulus to make changes.



American Stroke Association (2011). Blood types may be linked to higher stroke risk. News Tips. Retrieved from: http://newsroom.heart.org/pr/aha/wednesday-news-tips-nov-16-2011-218042.aspx

Fox News (2011). Blood Type May Affect Stroke Risk, Study Finds. Heart Health. Retrieved from: http://www.foxnews.com/health/2011/11/16/blood-type-may-affect-stroke-risk-study-finds/#ixzz1fgbl1slt