Age is a risk factor for this condition. Afib is most common in people over age 60, with the median age being 71. According to Dr. Singh, more people in their 50s and 60s are now presenting with Afib. This may be because doctors have gotten better at detecting it. Your lifestyle also can increase your risk of developing atrial fibrillation. Smoking, heavy drinking, and ongoing stress along with high blood pressure, diabetes, and obesity all can cause an abnormal heart rhythm. You’re at higher risk of having a stroke from Afib if you’re a woman or previously had a heart attack or stroke.