Narrowing of urine at the urethra may be the result of abnormalities such as mechanical obstruction and dynamic obstruction of the urinary system. 1. mechanical obstruction: when the urethra is compressed or its own narrowing occurs, the urine flows through the narrowed urethra, which can lead to narrowing of the urine when it is discharged, commonly seen in men with prostate hyperplasia and urethral stenosis and other diseases, which can result in the emergence of the urethra thinning and narrowing of the urine. 2. Dynamic obstruction: when the power of urination is abnormal, commonly seen in neurogenic bladder and forced urinary contraction weakness and other diseases, abnormal innervation caused by bladder contraction can not, can be manifested in the power of urination cross, even if the urethra is smooth, there can be a decrease in the flow rate of urine and urine narrowing situation. Urethral urine narrowing should be timely medical consultation, under the guidance of specialists actively line appropriate treatment, help early relief of uncomfortable symptoms.