The urinary system produces and stores urine
How the urinary system works Symptoms & Causes
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. In normal bladder function, you can usually control the release of urine.
The male urinary system:
Urinary incontinence is the involuntary or accidental leak of urine. There are different types of urinary incontinence, each with different causes and symptoms.
Neurogenic bladder refers to a condition where neurologic damage leads to bladder malfunction. This can mean that the bladder is unable to empty completely, called overactive bladder or urinary retention.
How common is urinary incontinence?
Although the exact number of people affected by urinary incontinence is unknown (many people never visit a healthcare professional or reveal their symptoms), urinary incontinence is much more common than you might think.
Studies suggest that between 20-50% of adult women are affected by urinary incontinence, many whom lead independent and active lives. And although urinary incontinence is less common in men, it still affects around 1 in 20 men aged 18 and above, and 1 in 10 men aged 60 and above.
Bladder dysfunction may result in urinary incontinence (accidental leakage of urine) or urine retention (incomplete emptying) – and some of the signs of urinary incontinence include:
- small or large amounts of urine leaking without warning or without feeling the urge to go to the bathroom
- urine accidentally leaking when sneezing, coughing, laughing or exercising
- a sudden urge to rush to the bathroom either before or during the leaking of urine
- urine escaping before getting to a toilet
- the need to get up to pass urine two or more times a night
- recent wetting of the bed
The most common types of urinary incontinence are stress urinary incontinence (SUI), urge urinary incontinence and mixed urinary incontinence.
- Stress urinary incontinence (SUI) occurs when the muscles in the pelvic floor, under sudden pressure or stress on the abdomen, are too weak to hold the urethral sphincters closed. The result is an accidental leakage of urine during everyday activities such as sneezing, coughing, laughing or exercising.
- Urge urinary incontinence (unstable or overactive bladder) is caused by involuntary, uncontrolled contractions of the muscle in the bladder. This results in a sudden urge to go to the bathroom, and accidental urine leakage before reaching the bathroom.
- Mixed urinary incontinence is a combination of stress urinary incontinence and urge urinary incontinence.
Neurogenic bladder is the term for a bladder that malfunctions due to neurological diagnosis. Because the bladder is controlled by nerves, neurological diseases or damage to the nervous system can affect bladder function and the process of urination. Neurogenic bladder can develop due to:
Urinary symptoms vary depending on where the neurological damage occurs and how severe it is. Bladder over-activity (spastic bladder) is associated with symptoms of urge incontinence, while sphincter under-activity (affecting the muscles that control the passage of urine out of the bladder) results in symptoms of stress incontinence - often a result of various prostate treatments.
- spinal cord injury
- neural tube defects including spina bifida
- brain tumors and other diseases of the brain
- diseases that affect the nerves including multiple sclerosis, type 2 diabetes and stroke
- major pelvic surgery
- normal aging process
Some neurologic disorders can cause urinary retention or completely prevent the bladder from emptying.