Urinary straining, also known as dyspareunia, is the result of reduced contraction of the bladder forcing muscles, increased resistance of the bladder outflow tract, either or both together. The search for the cause of dyspareunia is analyzed from two main aspects: first, increased resistance of the bladder outflow tract, the most common causes are prostatic hyperplasia, urethral stricture, fibrosis of the bladder neck opening, urethral stones, etc. Secondly, reduced contractile function of the bladder forceps muscle can also induce or maintain the normal forceps muscle contraction of the neuromuscular mechanism, caused by temporary or permanent damage in a link, the central nervous system, peripheral nerve function damage involved in the urinary reflex, neuromuscular signal transduction, bladder forceps muscle fibrosis and other lesions, can lead to bladder forceps muscle contraction incompetence resulting in difficulty in urination.