1: During pregnancy, the fetus accumulates the bladder and the bladder loses its elasticity.

2. Insufficient estrogen secretion in menopause leads to relaxation of urethral sphincter. Just as the elastic band loses its elasticity and becomes looser and looser, not only the urinary system is repeatedly infected, but also gynecological diseases will recur. The bacterial virus infiltrates upward and develops into nephritis and cystitis. Long-term relaxation of extensor muscles makes patients lose their self-care ability and stay in bed for a long time, relying on family and wife to take care of them.