Urinary Incontinence (UI)

What is urinary incontinence (UI)?

Normal urinary function is controlled by the brain, which sends signals to the muscles that control the urine flow, in particular the pelvic floor muscles. Urine is produced by the kidneys. It contains the waste products from the body — including toxins, salts and water — that collect in the blood. It is transported from the kidneys and excreted from the body via the urinary system. A person who is affected by urinary incontinence (UI), loses control of their urinary sphincter, the two muscles which control the passage of urine into the bladder, resulting in an involuntary leakage of urine.

UI is a symptom of other conditions, rather than a medical condition in its own right. People develop UI for a variety of reasons. It is generally associated with conditions which affect people in later life, such as prostate problems in men and the menopause in women.

Urine travels from the kidneys via the ureters (these are the connecting tubes between the kidneys and the bladder) to the bladder where it is stored until urination. In people with UI, the brain’s process of sending a signal to the bladder to release the urine can become compromised. This causes a person to be mentally unprepared for a sudden leakage of urine. In people with UI, the muscles in the bladder may also lose their functionality. This renders the bladder physically unprepared to contract and relax as needed in order to store urine effectively.

People affected by UI often experience a poorer quality of life than continent people. This is because the condition usually impacts significantly upon an individual’s daily routine. In severe cases, the condition can necessitate taking time off work and may cause physical sexual dysfunction due to an inability to control the timing of urination — as well as inspiring feelings of embarrassment and distress.[1]

However, in most cases, UI can be alleviated with correct management and/or treatment methods. These include learning behavioral techniques and following an exercise program to strengthen the pelvic floor muscles, Kegel exercises. In cases where an initial treatment plan does not alleviate UI, supplementary surgery may be considered. Alternatively, a long-term strategy for minimising the day-to-day impact of UI can be devised.


People affected by urinary incontinence (UI), experience loss of control over their urinary system. This can result in many different kinds of difficulties related to urinating, ranging from involuntary leakage to becoming unable to fully empty the bladder during urination.

UI can be transient[2]: a short-term or temporary problem which clears up on its own after the underlying cause, for example, a urinary tract infection, is resolved. However, UI can persist indefinitely. Ongoing cases of UI are described as chronic[2] and can be the result of long-term conditions which affect the production of urine and/or the urinary system, such as diabetes. Chronic UI can last indefinitely if left untreated, so it is important for anyone affected by UI to seek medical guidance.

The most common types of UI are stress incontinence, i.e.placing stress on the bladder during involuntary physical activities, such as sneezing or laughing causes an involuntary release of urine, and urge incontinence, which is a sudden and uncontrollable need to urinate.

There are six types of urinary incontinence:

  • Transient urinary incontinence: temporary, and directly related to a short-term condition being experienced by the affected person.
  • Stress urinary incontinence: due to pressure on the bladder from physical activity, such as sneezing or coughing.
  • Urge urinary incontinence: a sudden and intense need to urinate due to an overactive bladder.
  • Chronic urinary retention: feelings of having failed to fully empty the bladder after urination. This is also called overflow incontinence.
  • Functional urinary incontinence: an inability to urinate due to physical and mental obstacles.
  • Mixed urinary incontinence: this is when a person experiences two or more types of incontinence in combination. Stress and urge incontinence are the kinds of UI which are most commonly experienced together.

Transient urinary incontinence

Transient, short-term urinary incontinence can be caused by easily treatable factors, such as an adverse reaction to medication, and will clear up when the causal problem is remedied. In the first instance, when a person presents with UI, the doctor will determine whether the individual is affected by short-term UI and will then seek to treat the cause or causes.

In a case where UI is caused by an adverse reaction to medication, for example, this would involve stopping using the medication in question and prescribing a replacement option which is not associated with causing UI. Doctors often use a mnemonic — DIAPERS[3] — to explore the possible causes of transient UI and rule out a diagnosis.

Transient UI may be triggered by:

  • Delirium
  • Infection
  • Atrophy (when the pelvic floor muscles weaken due to underuse)
  • Pharmaceuticals
  • Excess urine output
  • Restricted mobility
  • Stool impaction

A person can be affected by several causes of transient UI simultaneously. In cases where UI may be caused by multiple factors, treating all the causes will maximise the chances of alleviating the UI. Pharmaceuticals which can cause UI principally do so by relaxing the bladder, increasing fluid retention, or inhibiting bladder contractions.[4] Medications which are often associated with the condition include anti-hypersensitives, pain relievers, psychotherapeutics (muscle relaxants) and others, such as antihistamine.

If none of the causes specified in the DIAPERS mnemonic are present, the doctor will begin to investigate other causes of UI, dependent on the specific symptoms of the individual.[2]

Stress urinary incontinence

Stress urinary incontinence is one of the two most common types of UI — the other being urge urinary incontinence. Stress incontinence is not related to feeling stressed. It occurs when the urethral sphincter, the pelvic muscles that support the bladder and control the progress of urine into the urethra, weakens. The urethral sphincter ceases to function to prevent the flow of urine into the bladder and when the bladder is put under sudden pressure, this results in involuntary leakages of urine.

Activities which may cause leakage of urine with stress incontinence include:

  • Coughing
  • Sneezing
  • Laughing
  • Exercise
  • Heavy lifting

People with stress incontinence usually experience small amounts of urinary leakage at intervals over the course of the day. More rarely, the condition can cause a person to involuntarily empty their bladder entirely.

Urge urinary incontinence (overactive bladder syndrome)

Urge urinary incontinence (overactive bladder syndrome) is one of the two most common types of UI — the other being stress urinary incontinence. Urge incontinence is also sometimes called urgency incontinence because it involves a sudden need to relieve the bladder, causing the affected person to release urine a few seconds after they feel the need to do so. Urge incontinence can be triggered by both physical and psychological factors.

Activities and actions which cause leakage of urine with urge incontinence include:

  • Sexual intercourse
  • Reaching orgasm
  • A rapid or sudden change of position
  • Hearing the sound of running water

People affected by urge incontinence may experience urinary leakage very frequently, and typically wake up several times during the course of the night to pass urine. It is not often possible for the doctor to identify a specific cause of urge incontinence, but it primarily affects women and the elderly.

Chronic urinary retention (overflow incontinence)

People affected by chronic urinary retention (overflow incontinence) cannot empty the bladder completely when they pass urine.

Chronic urinary retention can be the result of a mechanical obstruction, for example a urethral stricture (narrowing of the urethra caused by injury, infection or disturbance to the area from devices such as a catheter) or a dynamic obstruction, such as a loss of muscle tone, or by a combination of these factors. The condition can also be caused by the failure of the nervous system to transmit signals to the bladder.

People with chronic urinary retention are usually unaware that they are affected, until they develop a further symptom, such as a urinary tract infection (UTI) or lose their bladder control, resulting in an involuntary leakage of urine.

Rather than experiencing chronic, long-term urinary retention, a person can experience acute urinary retention, a short-term form of UI in which it becomes impossible to empty their bladder at all, even when it is full.[5] Acute urinary retention can be painful and potentially life-threatening, so it is vital to seek urgent medical attention.

Functional urinary incontinence

People experiencing functional urinary incontinence usually become aware that they need to urinate in advance of voiding their bladder. Their involuntary leakage of urine is caused by a range of possible physical and mental factors which prevent them from accessing the appropriate facilities in time.

Factors which contribute to functional urinary incontinence can include:

  • Dementia
  • Impaired dexterity
  • Confusion
  • Alzheimer’s disease
  • Parkinson’s disease
  • Depression
  • Anxiety
  • Poor eyesight (this may reduce a person’s ability to find their way to the restroom)

Functional urinary incontinence primarily affects the elderly, and people suffering from impaired mobility. It can involve either emptying the bladder fully or passing small amounts of involuntary urinary leakage.

Mixed incontinence

It is possible for a person to experience several types of UI simultaneously; this is called mixed incontinence. The most commonly experienced form of mixed incontinence involves being affected by both stress incontinence (leaking urine with activity) and urge incontinence (the sudden, uncontrollable urge to pass urine).

It is possible to manage and/or treat mixed incontinence with a treatment plan which addresses the triggers of all the types of UI present.

Causes of urinary incontinence

UI is a common problem which affects more women than men. UI most commonly affects elderly people because it is associated with many conditions that typically develop in later life, such as Parkinson’s disease and dementia.

UI may develop as a result of any of the following factors:

  • Another condition affecting the individual, for example, benign prostate hyperplasia
  • A number of different biological processes, for example pregnancy and the ageing of a person’s connective tissue, which can be influenced by their genetics and gender
  • A side-effect of medication
  • A complication relating to a surgical procedure

Conditions and procedures which are commonly associated with urinary incontinence include:

  • Urinary tract infections, which may be intermittent or chronic
  • Congenital or birth defects — problems with development of the urinary tract
  • Benign prostatic hyperplasia (BPH) — an enlarged prostate gland
  • Kidney failure
  • Vaginal prolapse
  • Injuries to the spinal and nervous system
  • Injuries to the pelvic area
  • Stroke
  • Diabetes
  • High blood pressure
  • Smoking tobacco
  • Alcohol abuse
  • Obesity
  • Interstitial cystitis (bladder pain syndrome)
  • Pregnancy: risk of UI increases with each pregnancy a person experiences
  • Prostatectomy (prostate surgery)
  • Menopause and postmenopausal complications

Because of the differences between the sexes in terms of pelvic and genital structure and the way the genitalia are connected to the urinary system, UI generally affects men and women differently in terms of the type of UI experienced, and for different reasons. Women are often affected by UI in relation to their reproductive processes, whereas men commonly experience UI in relation to problems affecting the prostate gland and associated surgery.

UI in women

Women are more likely to experience UI than men because they are, physiologically, more likely to undergo bodily changes which compromise the normal function of the urinary system. Women can be affected by all types of UI and at any age. However, UI in women is primarily associated with ageing and with natural biological processes.

For example, UI often accompanies pregnancy and also commonly affects women during or after they experience the stages of menopause.

The principal types of UI experienced by women are:

  • Stress incontinence
  • Urgency incontinence
  • Mixed incontinence

Women who have experienced pregnancy are more likely to experience UI. This is because being pregnant always involves changes to a person’s hormonal levels and an increase of pressure on their pelvic floor muscles as the developing fetus grows, which is likely to disrupt urinary function during the pregnancy as well as afterwards.

Giving birth itself, particularly vaginally, can alter the position of the pelvic floor muscles that control the flow of urine from the bladder, further increasing the chances of developing UI after being pregnant. However, the hormonal changes and stress to the pelvic floor involved in pregnancy, are the primary causes of UI in women rather than the actions involved in birth itself, so opting for a c-section will not significantly reduce a person’s likelihood of developing UI.

The risk of UI increases with the number of times a woman experiences pregnancy and childbirth. Both cesarean (c-section) and vaginal birthing methods can give rise to UI. Many women experience UI whilst going through the menopause, which involves a reduction in their accustomed estrogen levels. However, it is not thought possible to alleviate UI with any significant success by taking oral estrogen supplements; these can in fact worsen the condition.[6]

UI in men

Men can experience any of the types of UI. In men, UI primarily occurs because of developing problems with nerve function, such that the brain no longer sends signals to the bladder effectively. This can include suffering from a stroke or a spinal cord injury (SCI), both of which affect the nervous system, interrupting the transmission of the nerve signals required for control of the urinary sphincter. Men who are affected by problems related to the prostate gland are also at risk of experiencing UI.

The prostate gland is located beneath the bladder, inside the male body, between the bladder and the penis and produces about 30% of the body’s ejaculation fluid. Problems which affect the prostate and may be associated with UI, include:

  • Benign prostatic hyperplasia (prostate enlargement)
  • Prostate cancer
  • Prostatitis (swelling of the prostate gland)

All of these conditions can change the position of the urinary sphincter and/or exert pressure on the bladder, causing UI.

Prostate problems and associated cases of UI most commonly develop in later life. Men who have undergone treatment, such as radiation therapy for prostate cancer, or who have undergone a prostatectomy (prostate surgery) will experience urinary incontinence initially. This usually occurs after the urinary catheter, which facilitates urinary function in the initial postoperative period, is removed. UI associated with prostate surgery generally goes away with correct management and/or treatment, as the recovery period progresses.

For more information about the prostate and conditions that affect it, see [this collection](link to collected pages on prostate) of resources.

  1. Review The psychosocial impact of urinary incontinence in women.” The Obstetrician and Gynecologist. 18 July 2011.

  2. Diagnosis of Urinary Incontinence.” American Family Physician. 15 April 2013.

  3. Management of urinary incontinence in the elderly.” New England Journal of Medicine. 26 September 1985.

  4. Medications that can cause urinary incontinence.” Harvard Health Publications. December 2014.

  5. Acute urinary retention.” BJU International. January 2000.

  6. Is Estrogen for Urinary Incontinence Good or Bad?.” Reviews in Urology. Spring 2006.