Always sinus tachycardia at night may be excessive anxiety, hyperthyroidism, anemia and other diseases. 1. Excessive anxiety: the heart rate will slow down when people sleep at night, if excessive anxiety and nervousness, it will lead to nocturnal sympathetic excitation, manifested as sinus tachycardia. 2. Hyperthyroidism: the patient’s body thyroid hormone levels increased significantly, increased levels of thyroid hormones will appear faster heart rate, the symptoms may be more pronounced at night during sleep, you can give metoprolol to control the heart rate of treatment, and methimazole to control hyperthyroidism. 3. Anemia: Anemia can lead to relative lack of oxygen, the heart in order to meet the body’s demand for energy, will speed up the heart rate to maintain the normal conduct of life activities, the treatment should be dealt with to find the origin, in the blood at the same time as the treatment of the primary disease. The heart rate at night is about to pay attention to find the cause, the symptoms are obvious to the hospital in time, under the guidance of the physician, to carry out a detailed diagnosis and treatment.