The causes of fast heart rate after pituitary tumor surgery may be postoperative anxiety and tension, excessive blood or fluid loss, supraventricular tachycardia and so on. 1. Postoperative anxiety and tension: if the patient has anxiety and tension after pituitary tumor surgery, it will easily make the sympathetic nerves excited, and the patient will have the performance of rapid heart rate and transient elevation of blood pressure. 2. Excessive blood loss or fluid loss: if the patient has more blood loss after pituitary tumor surgery, or insufficient rehydration fluid after surgery. These will lead to insufficient circulating blood volume, which will easily cause the patient to have tachycardia. 3. Supraventricular tachycardia: emotional excitement or surgical stimulation after pituitary tumor surgery may cause supraventricular tachycardia, at this time, the patient will show increased heart rate, dizziness, shortness of breath, chest tightness and so on. 4. Others: fast heart rate after pituitary tumor surgery may also be caused by postoperative pain, atrial fibrillation and other factors. It is suggested that patients with pituitary tumor who have fast heart rate after surgery need to consult doctor in time, and the doctor will choose appropriate treatment measures according to the cause of the disease.