Urinary incontinence is defined as the inability to control urinary flow. Incontinence can be an occasional leakage as well as the complete inability to hold urine.
There are two main kinds of urinary incontinence:
- Stress incontinence. This occurs during physical activity like exercise, coughing, sneezing, or laughter.
- Urge incontinence. People with urge incontinence experience a strong, sudden need to urinate. This is followed very quickly by bladder contraction and involuntary urination, without enough time to act.
There are several alternative names, including:
- Loss of bladder control.
- Uncontrollable urination.
- Urination – uncontrollable.
- Incontinence – urinary.
Bowel incontinence is the inability to control the passage of stool. This is a separate topic.
The ability to hold urine depends on several factors, including:
- Normal anatomy.
- Normal function in the urinary tract and nervous system.
- Physical and psychological ability to recognize and respond to the urge to urinate.
There are two phases to the process of urination:
- During the filling and storage phase, the kidneys send urine to the bladder. The bladder stretches to hold the increasing amounts of urine. Generally, you will begin to feel the urge to urinate when your bladder contains about 200 mL, or just under 1 cup, of urine. The average person can hold 350 to 550 mL, or over 2 cups, of urine. This ability depends on two muscles:
- The sphincter is a circular muscle which controls the opening of the bladder. Urination requires the sphincter to function correctly.
- The detrusor is a muscle that surrounds the bladder wall. It must be stable and expandable.
- The emptying phase relies on these muscles. The detrusor muscle contracts, squeezing the bladder to force urine out. At the same time, your sphincter must relax, allowing urine to leave the bladder and pass from your body.
There are many possible causes for urinary incontinence. These causes can differ, depending on whether the incontinence is sudden and temporary or long-term.
Here are some common causes of sudden or temporary incontinence:
- Bedrest – for example, following surgery.
- Certain medications – diuretics, antidepressants, tranquilizers, cough and cold remedies, and anti-allergy medications (antihistamines).
- Increased volume of urination – for example, due to poorly controlled diabetes.
- Mental confusion.
- Prostate infection or inflammation.
- Stool impaction from severe constipation – this can put pressure on the bladder.
- Urinary tract infection or inflammation.
- Weight gain.
Common causes of long-term urinary incontinence include:
- Alzheimer’s disease.
- Bladder cancer.
- Bladder spasms.
- Neurological conditions – including stroke or multiple sclerosis.
- Nerve or muscle damage resulting from pelvic radiation.
- Structural problems in the urinary tract.
- Spinal injury.
- Weakness of the sphincter – this can result from prostate surgery for men or vaginal surgery for women.
- Enlarged prostate in men.
- Pelvic prolapse in women – a falling or sliding of the bladder, urethra, or rectum into the vaginal space. This is often related to multiple pregnancy and childbirth.
Urinary incontinence is more common in women than men. Young (and sometimes teenage) girls may experience slight urine leakage when laughing.
Age is a major consideration. Urinary incontinence is most common in the elderly. Infants and children are not considered incontinent, but rather untrained. After toilet training, occasional accidents are not unusual up to the age of 6 years. Nighttime urination until this age is normal.