High renin activity is considered to be caused by physiological factors, but may also be caused by renal insufficiency, pheochromocytoma, renal artery stenosis and other disease factors, it is recommended to consult a doctor. 1. Physiological factors: poor rest or overwork, prolonged late night, excessive stress may cause sympathetic excitation, resulting in high renin activity. 2. Pathological factors: when the glomerular filtration rate decreases in renal insufficiency, the blood flow through the kidneys will be reduced, which leads to the production of more renin by the kidneys; pheochromocytoma can secrete a large amount of catecholamines, which will stimulate the sympathetic nerves and cause an increase in the secretion of renin. When high renin activity occurs, it is recommended to go to the hospital after excluding physiological factors, and ask the doctor to make a judgment to clarify the cause of the disease.