The reasons for not urinating after drinking a lot of water are as follows: 1. The body is seriously dehydrated, and the amount of water drunk is not enough to replenish the body with enough water, so the urine produced is very little and not excreted, so you need to continue drinking water and then observe whether the color of the urine is normal. 2. The water may have evaporated through other ways, such as if the patient suffers from respiratory diseases, frequent breathing will cause water to be exhaled out of the body If the patient has diarrhea, a large amount of water is discharged from the body, and the amount of water drunk does not reach the amount of water needed by the body, so the urine is very little and cannot be discharged. 3, kidney diseases, such as renal obstruction, renal failure, etc., will lead to kidney filtration disorders, and then water will accumulate in the body, and a large amount of water cannot be filtered by the kidneys to form urine and discharged from the body. These diseases will not only lead to urination, but also symptoms such as swelling of the face, swelling of the lower limbs and swelling of the abdomen.