Overactive bladder is characterized by a group of four symptoms: urgency, urinary frequency, nocturia, and urge incontinence. Urge incontinence is not present in the "dry" classification.

Urgency is considered the hallmark symptom of OAB, but there are no clear criteria for what constitutes urgency and studies often use other criteria. Urgency is currently defined by the International Continence Society (ICS), as of 2002, as "Sudden, compelling desire to pass urine that is difficult to defer." The previous definition was "Strong desire to void accompanied by fear of leakage or pain." The definition does not address the immediacy of the urge to void and has been criticized as subjective.

Urinary frequency is considered abnormal if the person urinates more than eight times in a day. This frequency is usually monitored by having the patient keep a voiding diary where they record urination episodes. The number of episodes varies depending on sleep, fluid intake, medications, and up to seven is considered normal if consistent with the other factors.

Nocturia is a symptom where the person complains of interrupted sleep because of an urge to void and, like the urinary frequency component, is affected by similar lifestyle and medical factors. Individual waking events are not considered abnormal, one study in Finland established two or more voids per night as affecting quality of life.

Urge incontinence is a form of urinary incontinence characterized by the involuntary loss of urine occurring for no apparent reason while feeling urinary urgency as discussed above. Like frequency, the person can track incontinence in a diary to assist with diagnosis and management of symptoms. Urge incontinence can also be measured with pad tests, and these are often used for research purposes. Some people with urge incontinence also have stress incontinence and this can complicate clinical studies.

It is important that the clinician and the patient both reach a consensus on the term, 'urgency.' Some common phrases used to describe OAB include, 'When I've got to go, I've got to go,' or 'When I have to go, I have to rush, because I think I will wet myself.' Hence the term, 'fear of leakage,' is an important concept to patients.

There is some controversy about the classification and diagnosis of OAB. Some sources classify overactive bladder into "wet" and "dry" variants depending on whether it is an urgent need to urinate or if it includes incontinence. Wet variants are more common than dry variants. The distinction is not absolute, one study suggested that many classified as "dry" were actually "wet" and that patients with no history of any leakage may have had other syndromes.

OAB is distinct from stress urinary incontinence, but when they occur together, the condition is usually known as mixed incontinence.

Urinary incontinence (UI), also known as involuntary urination, is any leakage of urine. It is a common and distressing problem, which may have a large impact on quality of life. It is twice as common in women as in men. Pelvic surgery, pregnancy, childbirth, and menopause are major risk factors. It has been identified as an important issue in geriatric health care. Urinary incontinence is often a result of an underlying medical condition but is under-reported to medical practitioners. Enuresis is often used to refer to urinary incontinence primarily in children, such as nocturnal enuresis (bed wetting).

There are four main types of incontinence:

- Urge incontinence due to an overactive bladder

- Stress incontinence due to poor closure of the bladder

- Overflow incontinence due to either poor bladder contraction or blockage of the urethra

- Functional incontinence due to medications or health problems making it difficult to reach the bathroom

Treatments include surgery, pelvic floor muscle training, bladder training, and electrical stimulation. The benefit of medications is small and long term safety is unclear.

Overflow incontinence occurs when the patient's bladder is always full so that it frequently leaks urine. Weak bladder muscles, resulting in incomplete emptying of the bladder, or a blocked urethra can cause this type of incontinence. Autonomic neuropathy from diabetes or other diseases (e.g. Multiple sclerosis) can decrease neural signals from the bladder (allowing for overfilling) and may also decrease the expulsion of urine by the detrusor muscle (allowing for urinary retention). Additionally, tumors and kidney stones can block the urethra. Spinal cord injuries or nervous system disorders are additional causes of overflow incontinence. In men, benign prostatic hyperplasia (BPH) may also restrict the flow of urine. Overflow incontinence is rare in women, although sometimes it is caused by fibroid or ovarian tumors. Also overflow incontinence can be from increased outlet resistance from advanced vaginal prolapse causing a "kink" in the urethra or after an anti-incontinence procedure which has overcorrected the problem. Early symptoms include a hesitant or slow stream of urine during voluntary urination. Anticholinergic medications may worsen overflow incontinence. NSAIDs medications may worsen overflow incontinence.

It is the loss of small amounts of urine associated with coughing, laughing, sneezing, exercising or other movements that increase intra-abdominal pressure and thus increase pressure on the bladder. The urethra is supported by fascia of the pelvic floor. If this support is insufficient, the urethra can move downward at times of increased abdominal pressure, allowing urine to pass.

Most lab results such as urine analysis, cystometry and postvoid residual volume are normal.

Some sources distinguish between urethral hypermobility and intrinsic sphincter deficiency. The latter is more rare, and requires different surgical approaches.

Overflow incontinence is a form of urinary incontinence, characterized by the involuntary release of urine from an overfull urinary bladder, often in the absence of any urge to urinate. This condition occurs in people who have a blockage of the bladder outlet (benign prostatic hyperplasia, prostate cancer, or narrowing of the urethra), or when the muscle that expels urine from the bladder is too weak to empty the bladder normally. Overflow incontinence may also be a side effect of certain medications.

Stress incontinence, also known as stress urinary incontinence (SUI) or effort incontinence is a form of urinary incontinence. It is due to insufficient strength of the closure of the bladder.

The most common types of urinary incontinence in women are stress urinary incontinence and urge urinary incontinence. Women with both problems have mixed urinary incontinence. After menopause, estrogen production decreases and in some women urethral tissue will demonstrate atrophy with the tissue of the urethra becoming weaker and thinner. Stress urinary incontinence is caused by loss of support of the urethra which is usually a consequence of damage to pelvic support structures as a result of childbirth. It is characterized by leaking of small amounts of urine with activities which increase abdominal pressure such as coughing, sneezing and lifting. 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 . It is characterized by leaking of large amounts of urine in association with insufficient warning to get to the bathroom in time.

- Polyuria (excessive urine production) of which, in turn, the most frequent causes are: uncontrolled diabetes mellitus, primary polydipsia (excessive fluid drinking), central diabetes insipidus and nephrogenic diabetes insipidus. Polyuria generally causes urinary urgency and frequency, but doesn't necessarily lead to incontinence.

- Enlarged prostate is the most common cause of incontinence in men after the age of 40; sometimes prostate cancer may also be associated with urinary incontinence. Moreover, drugs or radiation used to treat prostate cancer can also cause incontinence.

- Disorders like multiple sclerosis, spina bifida, Parkinson's disease, strokes and spinal cord injury can all interfere with nerve function of the bladder.

- Urinary incontinence is a likely outcome following a radical prostatectomy procedure.

- About 33% of all women experience UI after giving birth; women who deliver vaginally are about twice as likely to have urinary incontinence as women who give birth via a Caesarean section.

FI affects virtually all aspects of peoples' lives, greatly diminishing physical and mental health, and affect personal, social and professional life. Emotional effects may include stress, fearfulness, anxiety, exhaustion, fear of public humiliation, feeling dirty, poor body-image, reduced desire for sex, anger, humiliation, depression, isolation, secrecy, frustration and embarrassment. Some people may need to be in control of life outside of FI as means of compensation. The physical symptoms such as skin soreness, pain and odor may also affect quality of life. Physical activity such as shopping or exercise is often affected. Travel may be affected, requiring careful planning. Working is also affected for most. Relationships, social activities and self-image likewise often suffer. Symptoms may worsen over time.

Paradoxical anal contraction during attempted defecation in constipated patients was first described in a paper in 1985, when the term anismus was first used. The researchers drew analogies to a condition called vaginismus, which involves paroxysmal (sudden and short lasting) contraction of pubococcygeus (another muscle of the pelvic floor). These researchers felt that this condition was a spastic dysfunction of the anus, analogous to ‘vaginismus’. However, the term anismus implies a psychogenic etiology, which is not true although psychological dysfunction has been described in these patients. Hence:

Latin "ani" - "of the anus"

Latin "spasmus" - "spasm"

Many terms have been used synonymously to refer to this condition, some inappropriately. The term "anismus" has been criticised as it implies a psychogenic cause. As stated in the Rome II criteria, the term "dyssynergic defecation" is preferred to "pelvic floor dyssynergia" because many patients with dyssynergic defecation do not report sexual or urinary symptoms, meaning that only the defecation mechanism is affected.

Other synonyms include:

- Dyskinetic puborectalis

- Puborectalis syndrome

- Paradoxical puborectalis

- Nonrelaxing puborectalis

- Paradoxal puborectal contraction

- Spastic pelvic floor syndrome,

- Anal sphincter dyssynergia

- Paradoxical pelvic floor contraction

Anismus (or dyssynergic defecation) refers to the failure of the normal relaxation of pelvic floor muscles during attempted defecation.

Anismus can occur in both children and adults, and in both men and women (although it is more common in women). It can be caused by physical defects or it can occur for other reasons or unknown reasons. Anismus that has a behavioral cause could be viewed as having similarities with parcopresis, or psychogenic fecal retention.

Symptoms include tenesmus (the sensation of incomplete emptying of the rectum after defecation has occurred) and constipation. Retention of stool may result in fecal loading (retention of a mass of stool of any consistency) or fecal impaction (retention of a mass of hard stool). This mass may stretch the walls of the rectum and colon, causing megarectum and/or megacolon, respectively. Liquid stool may leak around a fecal impaction, possibly causing degrees of liquid fecal incontinence. This is usually termed encopresis or soiling in children, and fecal leakage, soiling or liquid fecal incontinence in adults.

Anismus is usually treated with dietary adjustments, such as dietary fiber supplementation. It can also be treated with a type of biofeedback therapy, during which a sensor probe is inserted into the person's anal canal in order to record the pressures exerted by the pelvic floor muscles. These pressures are visually fed back to the patient via a monitor who can regain the normal coordinated movement of the muscles after a few sessions.

Some researchers have suggested that anismus is an over-diagnosed condition, since the standard investigations or digital rectal examination and anorectal manometry were shown to cause paradoxical sphincter contraction in healthy controls, who did not have constipation or incontinence. Due to the invasive and perhaps uncomfortable nature of these investigations, the pelvic floor musculature is thought to behave differently than under normal circumstances. These researchers went on to conclude that paradoxical pelvic floor contraction is a common finding in healthy people as well as in people with chronic constipation and stool incontinence, and it represents a non-specific finding or laboratory artifact related to untoward conditions during examination, and that true anismus is actually rare.

FI may present with signs similar to rectal discharge (e.g. fistulae, proctitis or rectal prolapse), pseudoincontinence, encopresis (with no organic cause) and irritable bowel syndrome.

Athletic incontinence (athletic leakage, athletic leaks, exercise-induced urinary incontinence) is the specific form of urinary incontinence that results from engaging in high-impact or strenuous activities. Unlike stress incontinence, which is defined as the loss of small amounts of urine associated with sneezing, laughing or exercising, athletic incontinence occurs exclusively during exercise. Athletic incontinence is generally thought to be the result of decreased structural support of the pelvic floor due to increased abdominal pressure during high-impact exercise. As such exercises that build and develop the pelvic floor may be an important step to counteracting athletic incontinence. In addition to high-impact exercise, this weakening can also stem from childbirth and age.

There are often no symptoms associated with a urethrocele. When present, symptoms include stress incontinence, increased urinary frequency, and urinary retention (difficulty in emptying the bladder). Pain during sexual intercourse may also occur.

In voluntary urination, the bladder's normally relaxed detrusor muscle contracts to squeeze urine from the bladder.

One study, of 109 children diagnosed with giggle incontinence at Schneider Children's Hospital in New York, concluded that the cause of giggle incontinence is involuntary contraction of the detrusor muscle induced by laughter.

Because the complaint is difficult to reproduce under controlled conditions, its triggering mechanism is not clearly understood, but may be related to cataplexy, a sudden transient episode of loss of muscle tone often triggered by strong emotions.

There are a number of causes of functional incontinence. These include confusion, dementia, poor eyesight, impaired or dexterity or unwillingness to use the toilet due to depression or anxiety. Functional incontinence is more common in elderly people as many of the causes are associated with conditions that affect people as they age. For example, a person with Alzheimer's disease may not plan well enough to reach a bathroom in time or may not remember how to get to the bathroom.

Giggle incontinence, giggle enuresis or enuresis risoria is the involuntary release of urine in response to giggling or laughter. The bladder may empty completely or only partially.

Giggle incontinence is more common in children than adults, typically appearing at ages 5 to 7, and is most common in girls near the onset of puberty. The condition tends to improve with age, with fewer episodes during the teenage years, but may persist into adulthood. A survey of 99 student nurses indicated that about 25% had experienced such a wetting event during their lifetime, and about 10% were still susceptible in their late teens.

Giggle incontinence is a special form of urge incontinence, and is not the same as stress incontinence, which is generally brought on by participating in vigorous sport.

Functional incontinence can also occur at any age in circumstances where there is no apparent medical problem. For example, a person may recognise the need to urinate but are unable to do so because there is no toilet or suitable alternative nearby or access to a toilet is restricted or prohibited.

If a suitable place to urinate does not become available, the person may reach a stage where they are no longer able to refrain from urination and involuntary voiding of the bladder may take place. Instances of this sort will often result in full emptying of the bladder, but are likely to be one-off or rare occurrences. Excessive alcohol consumption can also cause episodes of incontinence in otherwise healthy adults.

Post-void dribbling or post-micturition dribbling is the where urine remaining in the urethra after voiding the bladder slowly leaks out after urination. A common and usually benign complaint, it may be a symptom of urethral diverticulum, prostatitis and other medical problems.

Men who experience dribbling, especially after prostate cancer surgery, will choose to wear incontinence pads to stay dry. Also known as guards for men, these incontinence pads conform to the male body. Some of the most popular male guards are from Tena, Depends, and Prevail. Simple ways to prevent dribbling include: strengthening pelvic muscles with Kegel exercises, changing position while urinating, or pressing on the perineum to evacuate the remaining urine from the urethra. Sitting down while urinating is also shown to alleviate complaints: a meta-analysis on the effects of voiding position in elderly males with benign prostate hyperplasia found an improvement of urologic parameters in this position, while in healthy males no such influence was found.

Finally, a small number of cases of incontinence are caused by physical problems in the urinary system in children. A condition known as urinary reflux or vesicoureteral reflux, in which urine backs up into one or both ureters, can cause urinary tract infections and incontinence. Rarely, a blocked bladder or urethra may cause the bladder to overfill and leak. Nerve damage associated with the birth defect spina bifida can cause incontinence. An ectopic ureter, a misplacement of the ureter outside the bladder, can also commonly cause incontinence. In these cases, the incontinence can appear as a constant dribbling of urine.

Enuresis (from the Ancient Greek ἐνούρησις "enoúrēsis") is a repeated inability to control urination. Use of the term is usually limited to describing people old enough to be expected to exercise such control. Involuntary urination is also known as urinary incontinence.

The symptoms of a cystocele may include:

- a vaginal bulge

- the feeling that something is falling out of the vagina

- the sensation of pelvic heaviness or fullness

- difficulty starting a urine stream

- a feeling of incomplete urination

- frequent or urgent urination

- fecal incontinence

- frequent urinary tract infections

A bladder that has dropped from its normal position and into the vagina can cause some forms of incontinence and incomplete emptying of the bladder.

Where a urethrocele causes difficulty in urinating, this can lead to cystitis.

Studies have shown that 30%-40% of all women deal with athletic incontinence, with some studies reporting up to 69% of women as sufferers. Athletes in high impact sports such as gymnastics and basketball are likely to suffer from incontinence, with over 60% of subjects in each sport reporting they suffer from athletic leaks during activity.

Rarely do sufferers of athletic incontinence seek treatment, with one study showing that over 95% of subjects had not sought professional advice on their condition. Those who participated in the study claimed they didn’t seek help because they were embarrassed or thought it was a normal condition.

Pelvic floor dysfunction refers to a wide range of issues that occur when muscles of the pelvic floor are weak, tight, or there is an impairment of the sacroiliac joint, lower back, coccyx, or hip joints. Symptoms include pelvic pain, pressure, pain during sex, incontinence, incomplete emptying, and visible organ protrusion. Tissues surrounding the pelvic organs may have increased or decreased sensitivity or irritation resulting in pelvic pain. Many times, the underlying cause of pelvic pain is difficult to determine. The condition affects up to 50% of women.

Pelvic floor dysfunction may include any of a group of clinical conditions that includes urinary incontinence, fecal incontinence, pelvic organ prolapse, sensory and emptying abnormalities of the lower urinary tract, defecatory dysfunction, sexual dysfunction and several chronic pain syndromes, including vulvodynia. The three most common and definable conditions encountered clinically are urinary incontinence, anal incontinence and pelvic organ prolapse.