Under normal circumstances, the daytime urine volume is greater than the nighttime (20:00 to 08:00) urine volume, and the ratio is about 2/1. As we grow older, the proportion of nighttime urine volume gradually increases, and by the age of about 60, the ratio of daytime urine volume to nighttime urine volume is about 1/1. Normal people urinate 2-3 times at night, and the total nighttime urine volume is 500ml (300-800ml) on average. If the amount of nighttime urine exceeds or equals the amount of daytime urine, and the number of urination increases, especially in the second half of the night, you still need to get up to urinate is called nocturia. It should be noted that nocturia emphasizes the total amount of urination at night, not the number of times of urination at night. Normal people may occasionally have increased nocturia, especially when they drink more water before going to bed, which is normal; it is not normal to have increased nocturia on a regular basis. The causes of increased nocturia are broadly divided into three categories: nocturia due to renal insufficiency, drainage, and mental. 1, nocturia of renal insufficiency: common in hypertensive kidney damage, small arteriosclerosis in the elderly, azotemia caused by various chronic kidney diseases, hypokalemic nephropathy (such as primary aldosteronism, etc.) and primary or secondary tubular-interstitial disease (such as tubular acidosis), etc. Increased nocturia in young people must be examined at a hospital, such as checking urinary routine, kidney function, and measuring blood pressure. 2. Drainage: It is common in cardiac insufficiency and various causes of edema or hydrothorax and ascites, where there is excessive water retention in the body. After lying in bed at night, blood circulation is improved and the retained water flows back into the blood easily, together with the lower position of the kidneys in the lying position and increased blood flow, so the volume of urination increases. 3.Spiritual nocturia: Due to mental tension, such as enuresis, frequent preventive urination at night often occurs, which can form a habit over time. However, those who increase the number of urination at night without an increase in urine volume do not belong to the category of nocturia.