Dabigatran is a drug for the prevention of thromboembolic disease in patients with non-valvular atrial fibrillation. Long-term oral administration can prevent cerebral infarction, heart attack, and lower extremity venous thrombosis in patients with atrial fibrillation, and should not be discontinued unless bleeding occurs as a side effect. The most common side effects include bleeding from the mouth and gums, bleeding while brushing the teeth, or petechiae or petechiae on the skin, or bleeding after a cut. Some more side effects are coughing up blood, vomiting blood, urinating blood, or black stools. In case of severe brain bleeding, it can manifest as headache; stomach bleeding can manifest as stomach pain. Women should also stop using dabigatran immediately and go to the hospital immediately if they have excessive menstrual flow during their physiological period. The side effect of bleeding usually occurs after long-term use of dabigatran, which puts the blood in an anti-hypercoagulable state.