Overactive bladder (OAB) is an uncomfortable feeling of urgently needing to pass urine. This feeling of urgency occurs frequently throughout the day and at night.

Sometimes it is difficult to hold the urine in, which causes leaking and incontinence.^{1   p5a}

Normally, the bladder acts like a balloon, becoming larger as it fills with urine draining from the kidneys. A muscular valve at the top of the urethra, the tube that drains the bladder, normally prevents leaking of urine. During normal urination, the valve relaxes and the muscle in the bladder wall contracts helping the bladder to empty.

OAB is extremely common. It is estimated that between 1 in 5 or 6 men and women over the age of 18 have symptoms. It becomes much more common with age, affecting 1 in 3 people aged 75 years or older. About a third of people with OAB have incontinence.^{1,2   1. p5b; 2. p786b}

To determine whether you have OAB and what treatment may be most appropriate for you, your doctor will ask you questions about your health and symptoms and perform a thorough examination. A urine specimen will be collected to send to the laboratory for analysis and to confirm that symptoms are not due to another cause, such as an infection. If necessary, you may be referred to a specialist doctor, such as a urologist or gynaecologist.

Your doctor may also ask you to keep a bladder diary to help keep track of symptoms, the number of times you need to pass urine during a 24 hour period and how much urine is passed. The diary will also help you to identify anything that is associated with urge and incontinence (e.g., sneezing, lifting, running).

Other tests that may be performed by a urologist include ultrasound, to help determine bladder function, and cystoscopy to look inside the bladder.^{1,2  1. p11a, p14a; 2. P788a-789a}