Micturition

After the toddler years, incontinence is usually a result of  emotional problems, physical pressure during pregnancy,  or nervous system problems. In stress incontinence, a sudden increase in intra-abdominal pressure (during laughing and coughing) forces urine through the external sphincter. This condition is common during pregnancy when the heavy uterus stretches the muscles of the pelvic floor and the urogenital diaphragm that support the external sphincter. In overflow incontinence, urine dribbles from the urethra whenever the bladder overfills.

In urinary retention, the bladder is unable to expel its contained urine. Urinary retention is normal after general anesthesia (it seems that it takes a little time for the detrusor to regain its activity). Urinary retention in men often reflects hypertrophy of the prostate, which narrows the urethra, making it difficult to void. When urinary retention is prolonged, a slender rubber drainage tube called  a catheter must be inserted through the urethra to drain the urine and prevent bladder trauma from excessive stretching.