Hypertension can be categorized into two main groups: primary and secondary. In the vast majority of patients, the cause of hypertension is unknown and is generally referred to as primary hypertension, which accounts for a relatively high percentage of cases. Secondary hypertension refers to elevated blood pressure caused by certain identified diseases or etiologies, in fact, elevated blood pressure is only a clinical manifestation of the disease. The main diseases that cause secondary hypertension are renal disease, endocrine disease, vascular lesions, cranial lesions, and hypertension during pregnancy. Primary hypertension is mostly considered to be related to gender and age, occupation, irrational diet, smoking, obesity, heredity, and mental and psychological factors. The diagnosis of hypertension must exclude secondary hypertension, never use antihypertensive drugs indiscriminately, if there is any suspicious symptom or discomfort, consult the doctor in time.