Overactive Bladder

The “overactive bladder” or OAB is characterized by:

  • urgency (see definitions), associated with;

  • frequency and;

  • nocturia.

It may be severe enough to result in urge incontinence.

What causes OAB?

OAB is caused by involuntary contractions of the Detrusor (bladder) muscle, often because of abnormal firing of the bladder nerves. It is a bit like an arrhythmia of the heart – but in the bladder!

There is usually no specific cause as to why the bladder behaves this way (idiopathic OAB), but it can result from neurological abnormalities such as:

  • Parkinson’s Disease.

  • CVA – stroke.

  • Multiple sclerosis.

  • Spinal injury etc.

What else could it be?

A number of conditions can mimic the symptoms of OAB:

  • Urinary tract infection – UTI.

  • Interstitial Cystitis.

  • Bladder cancer.

  • Conditions that cause fluid disturbance within the body e.g. heart and lung disease, renal (kidney) abnormalities.

How common is it?

OAB is very common with more than 15% of women older than 40 years suffering from the condition and more than 10% of men. As men get older (and their prostate grows) they also suffer from OAB even more frequently.

OAB can severely affect the quality of life not only of the person who suffers from it, but also their family and colleagues.

How is it investigated?

You may require some or all of the following tests:

  • Bladder Diary – often also known as a frequency volume chart.

  • Urine test – MSU – to rule out infection.

  • Blood tests – FBC; renal and liver function tests; blood sugar level (BSL) to exclude other diseases.

  • Urinary tract imaging – usually ultrasound.

  • Urodynamic test – Examine response of bladder.

  • Cystoscopy – a telescopic inspection of the bladder looking for local pathology that may be triggering the OAB.

Can it be treated?

There are many available treatment options for OAB, with the majority of people responding favourably to one treatment or the other.

Lifestyle Changes

  • Change in the amount or timing of fluid intake can have a profound effect on the severity of OAB. Most adults do not need more than 1500ml of fluid/day to remain healthy. You should not restrict fluid too much however.

  • Decreasing the amount of coffee, tea, alcohol and carbonated drinks can also decrease the irritable bladder.

  • Decrease the amount of highly spiced foods and tomato-based products

  • Ensuring the bowel habit is regular and preventing constipation is helpful

  • Weight loss – there is some evidence that even moderate weight loss can be beneficial in improving the symptoms of OAB.

  • Bladder and pelvic floor training.


  • Anti-muscarinic drugs – these work by decreasing urgency and increasing bladder capacity. At present there are two broad types available in Australia:

    • Non-specific: e.g. Oxybutynin, Probanthine – these are available on the PBS.

    • Specific (M3-antagonists): Solifenacin (Vesicare); Darifenacin (Enablex) – these are not available on the PBS.

  • Beta3 Agonist: Mirabegron (Betmiga) works via a different pathway to the anti-muscarinic drugs, actively promoting relaxation of the bladder muscle. There are fewer side effects with this drug, and it is possible to combine it with the other types of medication without significant increase in the chance of side-effects.

  • Botulinum toxin – “BOTOX” – this has proved a very effective drug in the treatment of OAB, especially if incontinence is significant. It blocks the “synapses” hence stops the abnormal nerve transmission.


  • Neuromodulation utilizes low pulse electrical stimulation to help regulate the abnormal nerve impulses that cause OAB.

  • It can be regarded as a similar therapy to a pacemaker used to regulate heart arrhythmias.

  • Once the neuromodulator is sited, it is possible to “fine tune it” to the individual patient. This is done simply and easily as an outpatient, utilizing a control unit.

  • Visit Restore Your Freedom website to learn more about Neuromodulation.