Most people with high blood pressure have an unknown cause, which used to be called primary hypertension and is currently called hypertension. In cases where there is a definite disease or cause for the increase in blood pressure, it is called secondary hypertension. To determine the cause of hypertension, it is necessary to take a medical history and perform a physical and laboratory examination. 1. Medical history: It is necessary to know whether there is a family history of hypertension, the duration of the disease, the lifestyle and the onset of symptoms, in order to determine whether there is a possibility of secondary hypertension. 2. Physical examination: Observe whether the patient has hyperthyroidism and proptosis, and check whether there is any kidney enlargement or mass in the abdomen, etc., to further exclude the possibility of secondary hypertension. 3. Laboratory examination: including blood routine, urine routine, renal function, electrocardiogram, echocardiogram, funduscopic examination, hypertension five, sleep respiratory monitoring and so on. Through the examination, it is clear whether there is any damage to the heart, brain and kidney as well as to exclude aortic valve closure insufficiency and renal diseases that lead to elevated blood pressure. Hypertensive patients should consult the cardiovascular medicine department of the hospital and under the guidance of the doctor for examination and treatment to clarify the causes leading to hypertension and subsequently carry out targeted treatment.