According to the latest definitions of the World Hypertension League and the Chinese Hypertension League, hypertension is a state of abnormally high arterial blood pressure, i.e., a systolic blood pressure (high pressure) equal to or exceeding 18.6 kPa (140 mm Hg) or a diastolic blood pressure (low pressure) equal to or exceeding 12 kPa (90 mm Hg). Either systolic or diastolic blood pressure is diagnosed as hypertension if one of these criteria is met. It is important to note that the above blood pressure refers to the brachial blood pressure of the upper extremities measured in a quiet state. Hypertension can be divided into two categories, primary hypertension and secondary hypertension, depending on whether the cause is clear. Primary hypertension is hypertension of unknown etiology, and its occurrence is associated with many factors. Secondary hypertension has a very clear etiology, i.e., the hypertension is caused by some disease. Ninety to 95 percent of the hypertension seen clinically is primary hypertension. Currently, primary hypertension is mainly controlled by medications. Secondary hypertension can be caused by a variety of diseases, the common ones are: ① renal diseases, such as chronic nephritis, pyelonephritis and other causes of renal insufficiency. (2) Adrenal disorders, such as primary aldosteronism, Cushing’s syndrome, pheochromocytoma, etc. (3) Renal vascular disorders, such as renal artery stenosis caused by various reasons. (4) Large vessel disorders, such as congenital aortic narrowing, atherosclerosis or aortic stenosis caused by multiple aortitis, etc. ⑤ Cardiac disorders, such as severe aortic valve insufficiency, complete atrioventricular block, etc. Certain systemic disorders, such as hyperthyroidism, cerebrovascular accidents, etc. Some secondary hypertension can be treated by interventional means, mainly renal artery stenosis of various causes and congenital aortic constriction.