Urinary incontinence


Urinary incontinence, also known as involuntary urination, is any uncontrolled leakage of urine. It is a common and distressing problem, which may have a significant effect on quality of life. Urinary incontinence is common in older women and has been identified as an important issue in geriatric health care. The term enuresis is often used to refer to urinary incontinence primarily in children, such as nocturnal enuresis. UI is an example of a stigmatized medical condition, which creates barriers to successful management and makes the problem worse. People may be too embarrassed to seek medical help and attempt to self-manage the symptom in secrecy from others.
Pelvic surgery, pregnancy, childbirth, attention deficit hyperactivity disorder, and menopause are major risk factors. Urinary incontinence is often a result of an underlying medical condition but is under-reported to medical practitioners. There are four main types of incontinence:
Treatments include behavioral therapy, pelvic floor muscle training, bladder training, medication, surgery, and electrical stimulation. Treatments that incorporate behavioral therapy are more likely to improve or cure stress, urge, and mixed incontinence, whereas, there is limited evidence to support the benefit of hormones and periurethral bulking agents. The complications and long-term safety of the treatments is variable.

Causes

Urinary incontinence can result from both urologic and non-urologic causes. Urologic causes can be classified as either bladder dysfunction or urethral sphincter incompetence and may include detrusor overactivity, poor bladder compliance, urethral hypermobility, or intrinsic sphincter deficiency. Non-urologic causes may include infection, medication or drugs, psychological factors, polyuria, hydrocephalus, stool impaction, and restricted mobility. The causes leading to urinary incontinence are usually specific to each sex, however, some causes are common to both men and women.

Women

The most common types of urinary incontinence in women are stress urinary incontinence and urge urinary incontinence. Women that have symptoms of both types are said to have "mixed" urinary incontinence. After menopause, estrogen production decreases and, in some women, urethral tissue will demonstrate atrophy, becoming weaker and thinner, possibly playing a role in the development of urinary incontinence.
Stress urinary incontinence in women is most commonly caused by loss of support of the urethra, which is usually a consequence of damage to pelvic support structures as a result of pregnancy, childbirth, obesity, age, among others. About 33% of all women experience urinary incontinence after giving birth, and women who deliver vaginally are about twice as likely to have urinary incontinence as women who give birth via a Caesarean section. Stress incontinence is characterized by leaking of small amounts of urine with activities that increase abdominal pressure such as coughing, sneezing, laughing and lifting. This happens when the urethral sphincter cannot close completely due to the damage in the sphincter itself, or the surrounding tissue. Additionally, frequent exercise in high-impact activities can cause athletic incontinence to develop. Urge urinary incontinence, is caused by uninhibited contractions of the detrusor muscle, a condition known as overactive bladder syndrome. This type of urinary incontinence is more commonly seen in women of older age. It is characterized by leaking of large amounts of urine in association with insufficient warning to get to the bathroom in time.

Men

is the most common type of incontinence in men. Similar to women, urine leakage happens following a very intense feeling of urination, not allowing enough time to reach the bathroom, a condition called overactive bladder syndrome. In men, the condition is commonly associated with benign prostatic hyperplasia, which causes bladder outlet obstruction, a dysfunction of the detrusor muscle, eventually causing overactive bladder syndrome, and the associated incontinence.
Stress urinary incontinence is the other common type of incontinence in men, and it most commonly happens after prostate surgery. Prostatectomy, transurethral resection of the prostate, prostate brachytherapy, and radiotherapy can all damage the urethral sphincter and surrounding tissue, causing it to be incompetent. An incompetent urethral sphincter cannot prevent urine from leaking out of the urinary bladder during activities that increase the intraabdominal pressure, such as coughing, sneezing, or laughing. Continence usually improves within 6 to 12 months after prostate surgery without any specific interventions, and only 5 to 10% of people report persistent symptoms.

Both

Adults

The body stores urine—water and wastes removed by the kidneys—in the urinary bladder, a balloon-like organ. The bladder connects to the urethra, the tube through which urine leaves the body.
Continence and micturition involve a balance between urethral closure and detrusor muscle activity. During urination, detrusor muscles in the wall of the bladder contract, forcing urine out of the bladder and into the urethra. At the same time, sphincter muscles surrounding the urethra relax, letting urine pass out of the body. The urethral sphincter is the muscular ring that closes the outlet of the urinary bladder preventing urine to pass outside the body. Urethral pressure normally exceeds bladder pressure, resulting in urine remaining in the bladder, and maintaining continence. The urethra is supported by pelvic floor muscles and tissue, allowing it to close firmly. Any damage to this balance between the detrusor muscle, urethral sphincter, supportive tissue and nerves can lead to some type of incontinence.
For example, stress urinary incontinence is usually a result of the incompetent closure of the urethral sphincter. This can be caused by damage to the sphincter itself, the muscles that support it, or nerves that supply it. In men, the damage usually happens after prostate surgery or radiation, and in women, it's usually caused by childbirth and pregnancy. The pressure inside the abdomen is normally transmitted to both urethra and bladder equally, leaving the pressure difference unchanged, resulting in continence. When the sphincter is incompetent, this increase in pressure will push the urine against it, leading to incontinence.
Another example is urge incontinence. This incontinence is associated with sudden forceful contractions of the detrusor muscle, leading to an intense feeling of urination, and incontinence if the person does not reach the bathroom on time. The syndrome is known as overactive bladder syndrome, and it's related to dysfunction of the detrusor muscle.

Children

Urination, or voiding, is a complex activity. The bladder is a balloon-like muscle that lies in the lowest part of the abdomen. The bladder stores urine and then releases it through the urethra, which is the canal that carries urine to the outside of the body. Controlling this activity involves nerves, muscles, the spinal cord and the brain.
The bladder is made of two types of muscles: the detrusor and the sphincter. The detrusor is a muscular sac that stores urine and squeezes to empty. Connected to the bottom or next of the bladder, the sphincter is a circular group of muscles that automatically stays contracted to hold the urine in. It will automatically relax when the detrusor contracts to let the urine into the urethra. A third group of muscles below the bladder can contract to keep urine back.
A baby's bladder fills to a set point, then automatically contracts and empties. As the child gets older, the nervous system develops. The child's brain begins to get messages from the filling bladder and begins to send messages to the bladder to keep it from automatically emptying until the child decides it is the time and place to void.
Failures in this control mechanism result in incontinence. Reasons for this failure range from the simple to the complex.

Diagnosis

The pattern of voiding and urine leakage is important as it suggests the type of incontinence. Other points include straining and discomfort, use of drugs, recent surgery, and illness.
The physical examination looks for signs of medical conditions causing incontinence, such as tumors that block the urinary tract, stool impaction, and poor reflexes or sensations, which may be evidence of a nerve-related cause.
Other tests include:
  • Stress test – the patient relaxes, then coughs vigorously as the doctor watches for loss of urine.
  • Urinalysis – urine is tested for evidence of infection, urinary stones, or other contributing causes.
  • Blood tests – blood is taken, sent to a laboratory, and examined for substances related to causes of incontinence.
  • Ultrasound – sound waves are used to visualize the kidneys and urinary bladder, assess the capacity of the bladder before voiding, and the remaining amount of urine after voiding. This helps know if there's a problem in emptying.
  • Cystoscopy – a thin tube with a tiny camera is inserted in the urethra and used to see the inside of the urethra and bladder.
  • Urodynamics – various techniques measure pressure in the bladder and the flow of urine.
People are often asked to keep a diary for a day or more, up to a week, to record the pattern of voiding, noting times and the amounts of urine produced.
Research projects that assess the efficacy of anti-incontinence therapies often quantify the extent of urinary incontinence. The methods include the 1-h pad test, measuring leakage volume; using a voiding diary, counting the number of incontinence episodes per day; and assessing of the strength of pelvic floor muscles, measuring the maximum vaginal squeeze pressure.