Want to urinate but can not come out may be too little water, nervousness and other physiological factors, or consider the prostate hyperplasia, urethral stenosis and other diseases. 1. Physiological factors: If you drink too little water, nervousness, hot environment, may lead to want to urinate but can not come out. If this happens for a short period of time, it is a normal phenomenon and there is no need to worry too much. 2. Prostatic hyperplasia: Prostatic hyperplasia may be caused by poor hygiene habits, inflammation, cell proliferation and other factors. Patients may have progressive urinary difficulties, with the degree of obstruction increases, patients may appear to prolong the time of urination, difficult urination, manifested as want to urinate but can not urinate. 3. Urethral stenosis: Urethral stenosis may be caused by trauma, surgical trauma, infection, genetics and other factors. Patients may have symptoms such as inability to urinate, urinary retention, urinary incontinence, etc., and some of them show that they want to urinate but cannot do so. To summarize, there are many reasons for wanting to urinate but not being able to do so, and it is recommended that patients identify the causes of the disease in a timely manner.