There are several common causes of swelling and pain in the back of the head: First, when the patient’s blood pressure suddenly rises, such as high pressure greater than 180mmHg, the patient’s cerebral perfusion increases, cerebral edema, intracranial pressure rises, which will lead to the patient’s symptoms of swelling and pain in the back of the head, and the monitoring of the patient’s blood pressure can be a clear diagnosis. Second, patients with coronary artery disease, after taking nitroglycerin and other nitrate drugs, there will be a side effect of swelling and pain in the back of the head, after stopping the use of such drugs, the patient’s symptoms of swelling and pain in the back of the head will be gradually relieved, according to the patient’s medical history can be clearly diagnosed. Third, when the patient has hypoglycemia, due to the insufficient supply of energy needed for brain metabolism, cerebral nerve dysfunction, brain cell edema, etc., the patient will show swelling and pain in the back of the head. It is mostly seen in patients who have been eating poorly for a long period of time, or diabetic patients applying excessive glucose-lowering drugs, and blood glucose test can be used to make a clear diagnosis. Fourth, when patients have cerebral hemorrhage, subarachnoid hemorrhage and other hemorrhagic diseases, the blood clots compress the intracranial nerves of the patients, which will lead to the symptoms of swelling and pain in the back of the head, and the CT examination of the head can make a clear diagnosis.