As atrial fibrillation is a heart issue, the main cause of it is heart diseases, which include coronary artery disease, heart birth defects, heart failure, heart valve disease, weakened heart muscle (cardiomyopathy), rheumatic heart disease, and inflamed membrane or sac around the heart (pericarditis). Sometimes AFib occurs during a heart attack.
Other health conditions also have something to do with AFib. Diseases that raise the risk of it include sleep apnea, an overactive thyroid gland, obesity, diabetes, metabolic syndrome, high blood pressure, infections caused by a virus, and lung disease.
Your age and family exert an influence on the risk of AFib. As you grow older, especially after age 60, you're more likely to develop heart disease and other conditions that can cause AFib. If one of your blood relations has AFib, then your likelihood of having it is higher than ordinary people.
Furthermore, your lifestyle and habits play an important role. Smoking may set off AFib. Excessive intake of alcohol and caffeine also does no good to your heart.