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Overactive bladder


Overactive bladder (sometimes referred to as 'OAB') describes a range of symptoms, the commonest being a sudden urge to urinate. This is often accompanied by an increased number of urinations per day along with the need to urinate at night and possibly, the leaking of a small amount of urine - 'urge incontinence'.

It is relatively common, with ~13% of women and ~11% of men affected globally by the condition. Although it becomes more prevalent with age, it is not a 'normal' part of the aging process.


The condition may be caused by a number of factors. The process of urination starts with the brain signaling the bladder muscles to contract to squeeze the urine into the urethra (the tube connecting to the bladder to the penis or vagina).

The urethra itself is equipped a muscle called the urethral sphincter which prevents any leakage before you are ready to go. An overactive bladder may be caused by the signals from the brain coming too early (i.e. before the bladder is full) or by 'overactive' bladder muscles (called 'detrusor muscles'), where there are involuntary contractions, referred to as Detrusor Overactivity ('DO'). These involuntary contractions are thought to be the commonest cause of the condition.

The following factors may make a person more at risk of the condition:

  • Aging
  • Obesity
  • Women who have given birth vaginally
  • Men with prostate conditions
  • Women who are post menopause
  • Neurological conditions e.g. stroke / multiple sclerosis
  • Tumours or stones present in the bladder
  • Conditions relating to cognitive function e.g. dementia / Alzheimer’s
  • High consumption levels or either caffeine or alcohol
  • Urinary Tract Infections (UTI's)
  • Some medications, especially ones which either increase urine production or necessitate the intake of larger quantities of fluid


The most common symptom is the sudden urge to urinate. This in turn can cause:

  • Need to urinate often (needing to urinate more than 8 times in any 24-hour period is regarded as 'frequent urination')
  • Needing to wake up more than once to urinate at night (this is called 'nocturia')
  • Incontinence

Tests / Diagnosis

To enable an accurate diagnosis of the cause of the condition, the doctor will need to:

  • Review your medical history
  • Ask about your normal fluid intake levels, diet, medications
  • Perform a physical examination of the abdominal and genital areas
  • Conduct a urine test to ascertain if there are any abnormalities indicating infection or other issues

Further tests may involve:


Where a camera is inserted via the urethra into the bladder to examine the urethra and bladder.


To assess the structure of the kidneys and the bladder and the ability of the bladder to empty completely.

Urodynamic testing

A range of tests to determine the function of the lower urinary tract.

CT scan / MRI scan

These scans are used to detect a possible neurological cause of the symptoms – i.e. disc prolapse, multiple sclerosis.


Treatment of an overactive bladder is performed in a stepwise manner. This is as follows:

  • Conservative measures: Reduce intake of bladder irritants (caffeine, alcohol, spicy foods), reduce excessive intake of fluid, rationalise medications, engage in pelvic floor physiotherapy
  • Medications: There are medications which act to prevent the bladder from contracting when it shouldn’t – your doctor will try you on a number of these before proceeding with more invasive treatment
  • Intravescal Botox or sacral neuromodulation: Botox is a potent neurotoxin which acts to prevent the bladder from contracting when it shouldn’t – its effects can last from 3 to 12 months. Sacral neuromodulation is the insertion of an electrical device to help modulate signals from the bladder to the brain and help to control the symptoms of an overactive bladder
  • Bladder augmentation: An operation where a piece of bowel is attached to the bladder to increase its capacity
  • Cystectomy: The removal of the bladder; a last resort for those who have debilitating symptoms and all other treatments have failed

Related Information

Intravesical Botox
Sacral neuromodulation