The increase of renin may be caused by the physiological factors, blood loss, renal insufficiency, adrenal gland occupation and so on. 1. Physiological factors: poor rest, overwork, excessive stress, staying up late for a long time, smoking and drinking alcohol, drinking strong tea and coffee, etc., can lead to increased sympathetic excitability, which can lead to increased renin. 2. Excessive blood loss: generally trauma blood loss, or gastric bleeding and other reasons, resulting in a decrease in the body’s effective circulating blood volume, resulting in a decrease in blood pressure, the body’s reflexive increase in renin, which can effectively improve blood pressure and reduce the occurrence of shock. 3. Renal insufficiency: Generally there is a decrease in glomerular filtration rate, i.e., renal insufficiency, at this time the blood flow through the kidneys of the human body will be reduced, and naturally it will stimulate the kidneys of the human body to produce more renin, which will lead to an increase in renin. 4. Adrenal occupation: generally refers to pheochromocytoma secretes a lot of catecholamines, which can stimulate the sympathetic nerve, and then promote renin secretion, so that renin increases. There are many other reasons for renin increase, so we suggest that patients with renin increase should go to regular hospitals in time to check the cause of the disease, and carry out standardized treatment under the guidance of doctors.