It is often associated with overactivity of the detrusor urinae muscle, a pattern of bladder muscle contraction observed during urodynamics. It is also possible that the increased contractile nature originates from within the urothelium and lamina propria, and abnormal contractions in this tissue could stimulate dysfunction in the detrusor or whole bladder. Catheter-related irritation
If bladder spasms occur or there is no urine in the drainage bag when a catheter is in place, the catheter may be blocked by blood, thick sediment, or a kink in the catheter or drainage tubing. Sometimes spasms are caused by the catheter irritating the bladder, prostate or penis. Such spasms can be controlled with medication such as butylscopolamine, although most people eventually adjust to the irritation and the spasms go away. Diagnosis
Diagnosis of OAB is made primarily on the persons signs and symptoms and by ruling out other possible causes such as an infection. Urodynamics, a bladder scope, and ultrasound are generally not needed. Additionally, urine culture may be done to rule out infection. The frequency/volume chart may be maintained and cystourethroscopy may be done to exclude tumor and kidney stones. If there is an underlying metabolic or pathologic condition that explains the symptoms, the symptoms may be considered part of that disease and not OAB.Psychometrically robust self-completion questionnaires are generally recognized as a valid way of measuring a persons signs and symptoms, but there does not exist a single ideal questionnaire.
This frequency is usually monitored by having the person 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 person with overactive bladder both reach a consensus on the term, urgency. Some common phrases used to describe OAB include, When Ive got to go, Ive 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 people. Causes
The cause of OAB is unclear, and indeed there may be multiple causes.