Patients with atrial fibrillation often ask in outpatient clinic visits, “Why do I have atrial fibrillation? Is there a reason why atrial fibrillation occurs? In response to this question, many patients are puzzled, and now we provide a detailed answer. What is atrial fibrillation? Atrial fibrillation is a rapid, disorganized supraventricular arrhythmia, a condition in which the atria contract with uneven agitation, resulting in atrial fibrillation without effective contraction. The frequency of atrial excitation can be as high as 300 to 600 beats per minute. It is one of the most common arrhythmias today. Many patients with atrial fibrillation will always have no obvious symptoms when their heart rate is not too fast, and some patients will feel irregular heartbeat and will have intermittent cardiac arrest, but most of the patients will have panic, shortness of breath, chest tightness, dizziness, weakness and sweating when their heart rate is fast. When the heart rate is too fast, patients can experience a drop in blood pressure, profuse sweating, cardiac insufficiency and even shock. What are the causes of atrial fibrillation? There are many possible causes of atrial fibrillation. In earlier years, the most common cause of atrial fibrillation in China was rheumatic valvular heart disease (wind heart disease), especially rheumatic mitral stenosis. However, as the incidence of rheumatic heart disease decreases, the number of atrial fibrillation caused by it also decreases greatly. The incidence of non-valvular atrial fibrillation is significantly higher. Common possible causes include hypertension, cardiomyopathy, heart failure, hyperthyroidism, post cardiac surgery, advanced age, and genetic factors. Other studies have shown that long-term heavy drinking and smoking can increase the risk of AF; obesity can also significantly increase the risk of AF; and long-term sleep apnea can significantly increase the risk of AF. Other common triggers of atrial fibrillation include emotional stress, nervousness, late nights, high intake of caffeine, strong tea, and electrolyte disorders.