Hypertension is categorized as primary and secondary. The cause of primary hypertension is not yet known. The causes of secondary hypertension are renal disease, endocrine disease, cardiovascular disease, and other diseases. 1. Primary hypertension. The specific cause is not clear, may be related to heredity, age, bad habits and other triggering factors. 2. Secondary hypertension. Renal diseases such as glomerulonephritis, chronic pyelonephritis. Endocrine diseases such as pheochromocytoma, menopausal syndrome. Cardiovascular diseases such as aortic insufficiency, aortic constriction. Craniocerebral diseases such as brain tumor, traumatic brain injury. Other diseases such as sleep apnea syndrome, erythrocytosis, etc. The exact cause of high blood pressure is determined by a regular hospital examination and a doctor.