Nocturia refers to the amount of urine voided between 8:00 p.m. and 8:00 a.m. the next day, and increased nocturia means that the amount and number of urine voided during this time are more than during the day. Normal people urinate less than 2 times at night, and the total amount of nocturnal urine is about 500 ml on average, which is equivalent to 1/4 to 1/3 of the whole day’s urine output. if the amount of nocturnal urine exceeds the amount of urine during the day and the number of urination increases, especially if you still need to get up to urinate in the middle of the night after going to sleep, you have increased nocturnal urination. Most of the main causes of nocturia are kidney diseases, such as chronic glomerulonephritis, chronic pyelonephritis, hypertensive renal arteriosclerosis and chronic renal insufficiency. Kidney disease can make the kidney function is reduced, the kidneys can not be completely excreted during the day metabolites in the body, need to continue to excrete at night, resulting in increased nocturia. In addition, in case of cardiac insufficiency, the return blood volume increases after lying down at night, so that the renal blood flow increases accordingly and the urine volume also increases. Insomnia or psychoneurological diseases caused by mental factors can also lead to increased nocturnal urination, but the increase in the number of nocturnal urination is dominant, while the urine volume is not much. In addition, such as drinking a lot of water during the day, using diuretics or drinking too much water before going to bed, etc., the increase in urine volume and nocturia caused by these reasons is normal and need not be concerned.