More frequent urination while lying down may be caused by cystitis, mental psychological factors, and drinking too much water before bedtime. 1. Cystitis: the mucous membrane of the triangle and bladder neck caused by bacterial infection and cause mucous membrane erythema, erosion, urine irritation of the mucous membrane of the triangle or the mucous membrane of the bladder neck, can cause frequent urination, urinary urgency and other symptoms. 2. Reduced bladder capacity: Bladder occupying lesions, tuberculous bladder contracture or larger bladder stones and other diseases may reduce the bladder capacity, which in turn causes urinary frequency. 3. Drinking too much before bed: Drinking too much water while sleeping can cause the reabsorption capacity of the kidney to increase, urine increase, urination increase, you can drink less water before bed. Lying down when urinating more frequently may also be caused by other factors, if the symptoms of lying down when urinating more frequently, persistent and unrelieved, you need to go to the regular hospital in time for treatment, and strive for early recovery.