Urine is produced in the kidneys, and flows from the kidneys into the bladder via the ureters. The bladder stores urine until the urethra carries it out of the body. This flow, from the bladder to the urethra, is controlled by the urethral sphincters, which open and close the bladder outlet. The sphincters, in turn, are controlled by the pelvic floor muscles. The healthy bladder expels urine in a controlled, usually voluntary fashion, and the average person urinates 4-8 times a day.
Bladder activity is regulated by the central and peripheral nervous systems. You feel the need to urinate when the stretch receptors in the bladder tell the brain that the bladder is full. However, with bladder dysfunction, you may not be able to inhibit the urge to pass urine. Problems with the bladder may result in urinary incontinence or urine retention.
Urinary incontinence is the involuntary leakage of urine. There are different types of urinary incontinence, each with different symptoms and causes.
Urinary retention can be caused by an obstruction in the urinary tract, a bladder muscle weakness or by a neurogenic condition e.g. multiple sclerosis, spinal cord injury or spina bifida all of which interfere with signals between the brain and the bladder, resulting in a dysfunction in the urinary system.
Neurological conditions can cause damage to the nervous system affecting the bladder and resulting in urinary retention (see above) or an overactive bladder which has symptoms of both urge incontinence and leakage.
Find out more
Learn more about neurogenic bladder, symptoms and causes of urinary retention and urinary incontinence.