After drinking a lot of water, normal people will generally increase the volume of urine with it. Drinking more water and urinating less is divided into physiological and pathological, and pathology is mainly common in cases of chronic renal insufficiency, ureteral obstruction, and heavy sweating. Normal people in strenuous exercise or hot environment work operations, despite the large amount of water, urine volume will also be reduced. This is due to excessive sweating, the body produces anti-diuretic hormone to reduce urine production and prevent the body from losing too much water. However, in a natural state, if you drink a lot of water and urine volume decreases, you should be alert to the presence of disease. Chronic renal insufficiency is a condition in which the kidneys are not functioning properly and are unable to metabolize water out of the body, so oliguria is a common symptom, and in severe cases, congestive heart failure can occur. Chronic renal insufficiency can lead to anuria in the late stages, so it is important to seek medical attention in time to slow down the progress of the disease. Ureteral obstruction is an obstructive oliguria caused by the inability to transport urine from the ureter to the bladder. Ureteral obstruction is mostly accompanied by hydronephrosis, and timely treatment is recommended if the obstruction occurs bilaterally, otherwise it will affect kidney function. To sum up, in addition to physiological changes such as strenuous exercise, most of the cases are caused by diseases, so it is recommended to seek medical attention in time to avoid neglecting the condition and finally causing end-stage renal disease.