If you urinate very little, but urinate a lot, it is recommended to go to the hospital for examination and clarification. The common causes include the following: 1, acute infection of the urinary system, after the infection can cause increased sensitivity of the mucosa, a small amount of urine stored in the bladder can produce a strong sense of urination, so there will be an increase in the frequency of urination, but the volume of urine decreased, but also accompanied by painful urination, lumbago, urinary incomplete feeling and other symptoms, you need to carry out urine laboratory tests to finally confirm the diagnosis. 2, the presence of urinary stones, stones cause enhanced mucosal irritation, therefore causing increased frequency of urination but not much urine volume. In particular, stones in the lower ureter can cause symptoms such as frequent urination, low urine volume and urinary urgency, which need to be ruled out by further ultrasound examination of the urinary system.3. Overactive bladder syndrome, which is more common in women, is often seen with increased frequency of urination, but low urine volume and not accompanied by urinary urgency and pain, and no fever or infection symptoms. The cause of this condition is unknown and is related to excessive and frequent contractions of the bladder forceps, which require urodynamic testing to confirm the diagnosis.