R30-R39: Symptoms and signs involving the urinary system

R33: Retention of urine

The bladder collects the urine. When the bladder is full, one normally feels a need to urinate, and does so. You are unable to deliberately pass water. That can have various causes. The urethra may be blocked or narrowed, for example. Or the muscles and nerves in the bladder or urethra do not work properly. Not being able to urinate can cause pain. You may also pass water involuntarily.