Want to urinate but can not urinate consider is difficult to urinate, common causes are mechanical obstruction, power obstruction and mixed obstruction. 1. Mechanical obstruction: more common in the urinary tract malformations, such as urethral stenosis, congenital urethral valves, urethral tumors, stones and so on. 2. Dynamic obstruction: more common in various causes of nerve injury, such as diabetic peripheral neuropathy, surgical injury. 3. Mixed obstruction: more common in prostatitis, prostate hyperplasia, urinary tract infection, etc.. 4. Psychological factors: when the patient has panic, anxiety and other emotions, the body may be in a state of tension, resulting in taut urethral sphincter and contraction of the urethral muscles, leading to urination difficulties. Difficulty in urination may also be caused by other factors, it is recommended that patients go to the regular hospital in time to improve the urine routine, urinary ultrasound, urodynamics, cystoscopy and other related examinations when necessary, to clarify the cause of the disease and then treatment.