Sudden increase in urine volume, possible causes: 1, such as drinking more water in a short period of time, can cause a sudden increase in urine, drinking more water causes more blood circulation into the kidney filtration, the kidney will excrete more water, there is an increase in urine. 2, if oral diuretic drugs or consumption of diuretic fruits, such as watermelon, can cause a sudden increase in urine volume in a short period of time, after stopping the relevant drugs or fruit intake 3.If an acute infection of the urinary tract occurs, there can be congestion and edema of the bladder and urethral epithelium and increased sensitivity. The patient will have frequent urination, urinary urgency, painful urination, accompanied by lumbar pain, fever and other symptoms, need to carry out routine urine examination to further confirm the diagnosis. 4, if in cold weather, can appear increased urination, the patient has a history of causing frequent urination, such as suffering from prostatic hyperplasia, prostatitis, etc., or the elderly kidney function filtration capacity decreases over the years, can appear the filtration rate is reduced. A sudden increase in urine volume can occur in the presence of cold or lower ambient temperatures, without a history of urinary urgency, painful urination, or back pain.