In women with low urine, then the possible causes: first, drink less water or insufficient body fluid replenishment, such as patients sweating more, or have diarrhea, vomiting, etc., then you need to drink more water or carry out infusion rehydration to increase body fluid, which can make the urine volume increase. Second, when there is nephritis, there can be a decrease in the filtration rate of the kidneys. This is when body fluids are retained in the body and cannot be filtered out of the body through the kidneys, which can manifest as a decrease in urine output. The decrease in urine volume due to kidney disease is usually less than 400ml in 24 hours, and can be accompanied by changes such as facial swelling. Thirdly, if there are urethral obstructive diseases, such as bilateral ureteral stones, urethral stones, urethral tumors, etc., this can lead to the retention of urine in the body can not be discharged. If there is fluid accumulation in the kidneys, or if there is urinary retention, which manifests as oliguria. It may also be accompanied by pain in the area where the disease is located, such as back pain and abdominal pain. Ultrasound or CT examination of the urinary system is needed to further exclude.