Globally, up to 35% of the population over the age of 60 years is estimated to be incontinent.

In 2014, urinary leakage affected between 30% and 40% of people over 65 years of age living in their own homes or apartments in the U.S. Twenty-four percent of older adults in the U.S. have moderate or severe urinary incontinence that should be treated medically.

Bladder control problems have been found to be associated with higher incidence of many other health problems such as obesity and diabetes. Difficulty with bladder control results in higher rates of depression and limited activity levels.

Incontinence is expensive both to individuals in the form of bladder control products and to the health care system and nursing home industry. Injury related to incontinence is a leading cause of admission to assisted living and nursing care facilities. More than 50% of nursing facility admissions are related to incontinence.

In women, physical changes resulting from pregnancy, childbirth, and menopause often contribute to stress incontinence. Stress incontinence can worsen during the week before the menstrual period. At that time, lowered estrogen levels may lead to lower muscular pressure around the urethra, increasing chances of leakage. The incidence of stress incontinence increases following menopause, similarly because of lowered estrogen levels. In female high-level athletes, effort incontinence occurs in all sports involving abrupt repeated increases in intra-abdominal pressure that may exceed perineal floor resistance.

Many people with OAB symptoms had those symptoms subside within a year, with estimates as high as 39%, but most have symptoms for several years.

In addition to weight loss and exercise there are some behavioral changes that can improve stress incontinence. First decrease the amount of liquid that you are ingesting, and avoid drinking caffeinated beverages because they irritate the bladder. Spicy foods, carbonated beverages, alcohol and citrus also irritate the bladder and should be avoided. Quitting smoking can also improve stress incontinence because smoking irritates the bladder and can make you cough (putting stress on the bladder).

Incontinence happens less often after age 5: About 10 percent of 5-year-olds, 5 percent of 10-year-olds, and 1 percent of 18-year-olds experience episodes of incontinence. It is twice as common in girls as in boys.

The Gold standard for all Urinary incontinence is an urodynamic study that looks for bladder capacity, detrusor stability, contractility and voiding ability (Cystometry)

Lesions affecting sacral segments or peripheral autonomic fibres result in atonic bladder with loss of sphincteric coordination. This results in loss of detrusor contraction, difficulty in initiating micturition and overflow incontinence. Anticholinergic side effects of certain medications (for example, certain antipsychotics and antidepressants) may cause urinary retention which may lead to overflow incontinence. Alpha-adrenergic agonists may cause urinary retention by stimulating the contraction of the urethral sphincter. Calcium channel blockers may decrease the contractility of the smooth muscle tissue in the urinary bladder, causing urinary retention with overflow incontinence.

Epidural anesthesia and delivery also can cause the overflow incontinence.

Without diagnostic evaluation, the cause of UAB is unclear, as there are multiple possible causes. UAB symptoms can accurately reflect impaired bladder emptying due either to DU or obstruction (normal or large storage volumes, elevated post-void residual volume), or can result from a sense of incomplete emptying of a hypersensitive bladder (small storage volumes, normal or elevated postvoid residual volume). UAB potentially might also result from inaccurate perceptions of bladder function, such as in neurologic or psychiatric disease. DU itself is often linked to a weak detrusor muscle (impaired contractility), however this association is weak. Both UAB and DU have been associated with diminished sensitivity to bladder volumes rather than objective detrusor weakness, suggesting both symptoms (UAB) and function (DU) have a significant component of sensory dysfunction, leading to impaired bladder sensations and control (Smith et al., 2015).

The underlying contributors to UAB include neurologic disease, metabolic disease (e.g. diabetes), chronic bladder outlet obstruction (e.g. obstructive BPH or complications of anterior vaginal surgery), cognitive decline (such as with aging), psychiatric disorders, and adverse effects of medications. Additionally, structural abnormalities expanding the urinary reservoir beyond the bladder, such as massive vesicoureteral reflux or large bladder diverticulae, can result in UAB. While aging itself is often associated with UAB (and DU), there is scant evidence to support this claim.

Earlier reports estimated that about one in six adults in the United States and Europe had OAB. The prevalence of OAB increases with age, thus it is expected that OAB will become more common in the future as the average age of people living in the developed world is increasing. However, a recent Finnish population-based survey suggested that the prevalence had been largely overestimated due to methodological shortcomings regarding age distribution and low participation (in earlier reports). It is suspected, then, that OAB affects approximately half the number of individuals as earlier reported.

The American Urological Association reports studies showing rates as low as 7% to as high as 27% in men and rates as low as 9% to 43% in women. Urge incontinence was reported as higher in women. Older people are more likely to be affected, and prevalence of symptoms increases with age.

Any condition that impairs bladder and bladder outlet afferent and efferent signaling can cause neurogenic bladder.

It is often associated with spinal cord diseases (such as syringomyelia/hydromyelia), injuries (like herniated disks), and neural tube defects including spina bifida.

It may also be caused by brain tumors and other diseases of the brain, pregnancy and by peripheral nerve diseases such as: Diabetes, Alcoholism (and Vitamin B12 deficiency).

It is a common complication of major surgery in the pelvis, such as for removal of sacrococcygeal teratoma and other tumors.

Bladder tamponade is obstruction of the bladder outlet due to heavy blood clot formation within it. It generally requires surgery. Such heavy bleeding is usually due to bladder cancer.

Underactive Bladder Syndrome (UAB) describes symptoms of difficulty with bladder emptying, such as hesitancy to start the stream, a poor or intermittent stream, or sensations of incomplete bladder emptying. The physical finding of detrusor pressurization of insufficient strength or duration to ensure timely and efficient bladder emptying is properly termed "detrusor underactivity" (DU) (Abrams et al., 2002). Historically, UAB and DU (as well as others such as 'bladder underactivity') have been often used interchangeably (Rigby D, 2005), leading to both terminologic and pathophysiologic confusion.

Patients with UAB have a diminished sense of bladder filling and consequently are often found to have DU as an underlying finding, however bladder outlet obstruction and less frequently volume hypersensitivity ("OAB") can be associated with UAB symptoms (Chapple et al., 2015).

It has been estimated that VUR is present in more than 10% of the population. Younger children are more prone to VUR because of the relative shortness of the submucosal ureters. This susceptibility decreases with age as the length of the ureters increases as the children grow. In children under the age of 1 year with a urinary tract infection, 70% will have VUR. This number decreases to 15% by the age of 12. Although VUR is more common in males antenatally, in later life there is a definite female preponderance with 85% of cases being female.

Catheterization methods range from intermittent catheterization, which involves no surgery or permanently attached appliances, to the creation of a stoma, which bypasses the urethra to empty the bladder directly.

Intermittent catheterization is the use, several times a day, of straight catheters (which are usually disposable or single-use products) to empty the bladder. This can be done independently by the patient, or with help, in the case that the patient lacks the dexterity to manage the catheter. For patients who are unable to tolerate disposable straight catheters, a Foley catheter allows continuous drainage of urine into a sterile drainage bag that is worn by the patient.

Other treatments involve creation of a stoma that is continent and readily accepts a catheter. These are known as Mitrofanoff mechanisms. An example of this treatment is the creation of an Indiana pouch. Additionally, a muscarinic agonist like Bethanechol may also be used, particularly in the postpartum or postoperative period. Function of the stoma may be augmented by periodic injections of botulinum toxin to relax one of the two sphincters involved in normal urination. The effect is longer-lasting with botulinum toxin type A than with type B. This use of botulinum toxin is discussed at length in the French medical literature.

The American Urological Association recommends ongoing monitoring of children with VUR until the abnormality resolves or is no longer clinically significant. The recommendations are for annual evaluation of blood pressure, height, weight, analysis of the urine, and kidney ultrasound.

Cystitis is a urinary bladder inflammation that results from any one of a number of distinct syndromes. It is most commonly caused by a bacterial infection in which case it is referred to as a urinary tract infection.

Botulinum A toxin is a valuable alternative for patients who do not want surgical methods.

Some people with IC/BPS have been diagnosed with other conditions such as irritable bowel syndrome (IBS), fibromyalgia, chronic fatigue syndrome, allergies, Sjogren's syndrome, which raises the possibility that interstitial cystitis may be caused by mechanisms that cause these other conditions. There is also some evidence of an association between urologic pain syndromes, such as IC/BPS and CP/CPPS, with non-celiac gluten sensitivity in some patients.

In addition, men with IC/PBS are frequently diagnosed as having chronic nonbacterial prostatitis, and there is an extensive overlap of symptoms and treatment between the two conditions, leading researchers to posit that the conditions may share the same etiology and pathology.

Bladder sphincter dyssynergia (also known as detrusor sphincter dysynergia (DSD) (the ICS standard terminology agreed 1998) and neurogenic detrusor overactivity (NDO)) is a consequence of a neurological pathology such as spinal injury or multiple sclerosis. which disrupts central nervous system regulation of the micturition (urination) reflex resulting in dyscoordination of the detrusor muscles of the bladder and the male or female external urethral sphincter muscles. In normal lower urinary tract function, these two separate muscle structures act in synergistic coordination. But in this neurogenic disorder, the urethral sphincter muscle, instead of relaxing completely during voiding, dyssynergically contracts causing the flow to be interrupted and the bladder pressure to rise.

Some genetic subtypes, in some people, have been linked to the disorder.

- An antiproliferative factor is secreted by the bladders of people with IC/BPS which inhibits bladder cell proliferation, thus possibly causing the missing bladder lining.

- PAND, at gene map locus 13q22–q32, is associated with a constellation of disorders (a "pleiotropic syndrome") including IC/BPS and other bladder and kidney problems, thyroid diseases, serious headaches/migraines, panic disorder, and mitral valve prolapse.

Common causes include, but not limited to:

- Incomplete emptying of the bladder

- Irritable bladder

- Constipation

- Stress

- Urinary tract infection

- Urgency (not “making it” to the bathroom in time)

- Anatomic abnormality

- Poor toileting habits

- Small bladder capacity

- Medical conditions like overactive bladder disorder

Retrograde ejaculation occurs when semen, which would, in most cases, be ejaculated via the urethra, is redirected to the urinary bladder. Normally, the sphincter of the bladder contracts before ejaculation forcing the semen to exit via the urethra, the path of least resistance. When the bladder sphincter does not function properly, retrograde ejaculation may occur. It can also be induced deliberately by a male as a primitive form of male birth control (known as "coitus saxonicus") or as part of certain alternative medicine practices.

Urinary catheterization increases the risk for urinary tract infections. The risk of bacteriuria (bacteria in the urine) is between three and six percent per day and prophylactic antibiotics are not effective in decreasing symptomatic infections. The risk of an associated infection can be decreased by catheterizing only when necessary, using aseptic technique for insertion, and maintaining unobstructed closed drainage of the catheter.

Male scuba divers utilizing condom catheters and female divers utilizing external catching devices for their dry suits are also susceptible to urinary tract infections.

In young sexually active women, sexual activity is the cause of 75–90% of bladder infections, with the risk of infection related to the frequency of sex. The term "honeymoon cystitis" has been applied to this phenomenon of frequent UTIs during early marriage. In post-menopausal women, sexual activity does not affect the risk of developing a UTI. Spermicide use, independent of sexual frequency, increases the risk of UTIs. Diaphragm use is also associated. Condom use without spermicide or use of birth control pills does not increase the risk of uncomplicated urinary tract infection.

Women are more prone to UTIs than men because, in females, the urethra is much shorter and closer to the anus. As a woman's estrogen levels decrease with menopause, her risk of urinary tract infections increases due to the loss of protective vaginal flora. Additionally, vaginal atrophy that can sometimes occur after menopause is associated with recurrent urinary tract infections.

Chronic prostatitis in the forms of chronic prostatitis/chronic pelvic pain syndrome and chronic bacterial prostatitis (not acute bacterial prostatitis or asymptomatic inflammatory prostatitis) may cause recurrent urinary tract infections in males. Risk of infections increases as males age. While bacteria is commonly present in the urine of older males this does not appear to affect the risk of urinary tract infections.

A common cause of pneumaturia is colovesical fistula (communication between the colon and bladder). These may occur as a complication of diverticular disease.

Other key differentials:

- Crohn's disease

- Carcinoma of the colon or bladder

- A gas-producing UTI (emphysematous cystitis: rare).

Male scuba divers utilizing condom catheters or female divers using a She-p external catching device for their dry suits are also susceptible to pneumaturia.