Atrial fibrillation (AFib) affects the way blood flows through the heart and makes it vulnerable for forming clots, which can travel to the brain and cause a stroke. The risk of stroke in a person with AFib is 500% higher than in someone without the disease, so treatment to reduce stroke risk is essential. Anticoagulants, also called blood thinners, can help reduce the risk of stroke. Fatal bleeding while on an anticoagulant is rare, and for most AFib patients, the benefit of preventing AFib caused strokes outweighs the increased risk of bleeding. To learn more about stroke risk and AFib, visit our website at http://www.agingresearch.org/atrialfibrillation.