The effect of pressor, if summarized in a more succinct statement, is to increase blood pressure by bringing back water that the body would otherwise lose. However, when stated in detail, it is mainly through the ability of the renal system to reabsorb water back, which produces the effect of not allowing a person to urinate, thus constricting the peripheral blood vessels, and can cause constriction of the intestines, gallbladder, bladder, and other cavitary organs. Pressin is generally used in the treatment of central dysuria, sometimes to control polyuria caused by pituitary tumors or after traumatic brain injury, to avoid abnormal increases in urine output, which can cause electrolyte disorders in the body. Pressin can also be used in the esophagus, gastrointestinal digestive system of acute bleeding adjuvant therapy. Therefore, it must be applied according to the specific situation, commonly known as in order to reabsorb water and raise blood pressure.