Overactive Bladder Syndrome

What is overactive bladder syndrome?

Overactive bladder syndrome (OAB) is when you regularly get a sudden, strong urge to pass urine that's hard to put off, sometimes with very little warning. It happens because your bladder muscle squeezes at the wrong time, and it's a common, usually manageable condition rather than a sign of something more serious.

What are the symptoms of overactive bladder syndrome?

• Urgency: A sudden, compelling need to pass urine that's hard to defer, giving you little or no time to get to the toilet.
• Frequency: Needing to pass urine more often than usual, and in smaller amounts. Most people pass urine 6 to 8 times a day, though anywhere from 4 to 10 times can be normal for you if it doesn’t bother you.
• Nocturia: Getting up more than twice a night to pass urine, which can disturb your sleep. Nocturia can also have other causes besides OAB, so this particular symptom may not fully resolve even if your other symptoms improve with treatment.
• Urgency incontinence: If the urge is so intense you can't hold on, this can lead to an involuntary leak of urine.

What are the causes of overactive bladder syndrome and who is at risk?

OAB affects more than 1 in 10 adults, and around 12% of the whole adult population, including younger people, though it becomes more common with age; people over 65 are around twice as likely to be affected. In most cases, the exact cause is never identified.

Sometimes your bladder becomes overly sensitive and signals that it's full when there's only a small amount of urine inside it. In true OAB, the bladder muscle itself contracts unpredictably as it fills, rather than staying relaxed until you're ready to go.

Things that can trigger or worsen symptoms, or make you more likely to develop OAB, include:

• drinking a lot of alcohol or caffeine, or not drinking enough fluid, which lets your urine become concentrated and irritate your bladder
• constipation, which puts extra pressure on your bladder
• a urine infection, or a bladder or prostate infection
• an enlarged prostate
• pregnancy and hormone changes, including the menopause
• anxiety or stressful periods
• certain medicines, including high doses of water tablets (diuretics)
• neurological conditions, such as stroke, multiple sclerosis or Parkinson’s disease
• being female, having metabolic syndrome, or having a pelvic organ prolapse
• smoking or being overweight.

Are there different types of overactive bladder syndrome?

Most OAB is described as idiopathic, meaning no specific cause is ever found, even after other conditions have been ruled out.

A smaller number of cases are linked to an underlying nervous system condition, such as stroke, multiple sclerosis or a spinal cord problem; this is sometimes called neurogenic detrusor overactivity, and because it's linked to a specific disease process, it usually needs more specialist input.

It's also worth distinguishing OAB from a related but different pattern sometimes called a hypersensitive bladder, where the bladder signals a false sense of fullness even though it hasn't actually contracted or filled much. Both can feel similar day to day, but they're assessed and treated in much the same way.

How is overactive bladder syndrome diagnosed?

Your doctor or specialist nurse will ask about your symptoms and general health, and may examine you, which can include an internal examination. You'll be asked to give a urine sample to rule out infection, and to keep a bladder diary, usually for 3 days, recording when and how much urine you pass.

You may also have a flow test, where you pass urine into a machine that measures the strength and pattern of your flow, sometimes combined with an ultrasound afterwards to check your bladder is emptying fully. Your doctor will also want to rule out other explanations for your symptoms, such as a urine infection, bladder stones, or, rarely, a bladder tumour, especially if you have any blood in your urine.

If your symptoms don't improve with initial treatment, you may be offered a more detailed test called urodynamics, which measures pressure inside your bladder as it fills and empties. This can confirm whether your bladder muscle is genuinely overactive, and helps guide further treatment, including whether more invasive options are appropriate.

How is overactive bladder syndrome treated?

Non-surgical treatment

Lifestyle changes

Simple changes to what and how much you drink are usually the first step. To avoid concentrated urine, it’s recommended that you drink around 2 litres (roughly 8 cups) of fluid every day.

Drinks and foods that can irritate the bladder and are worth cutting down on include tea and coffee (including decaffeinated), fizzy drinks, especially fizzy alcoholic drinks, drinks with artificial sweeteners such as aspartame, high-energy drinks, hot chocolate, green tea, alcohol generally, and acidic drinks and foods such as citrus fruit, blackcurrant juice and tomatoes. Water, herbal and fruit teas, milk, and diluted squash are all considered kinder to the bladder.

Reducing what you drink in the few hours before bed, while keeping your total intake up earlier in the day, can help with nocturia specifically.

Bladder training

This aims to help you gradually hold larger volumes more comfortably. One approach is to pass urine at fixed times, starting hourly and slowly extending the interval, week by week, up to 3 hours or more.

Another is to delay for a set period after you first feel the urge, starting with whatever you can manage, such as a minute, and building this up gradually towards 30 to 60 minutes. Distraction techniques can help you get through the urge, such as pelvic floor squeezes, curling your toes, gently tapping the base of your spine, sitting on a rolled-up towel, or focusing your mind on something else entirely.

Bladder training takes real commitment – you may notice some change within 6 to 8 weeks, but lasting improvement can take 3 to 6 months. It isn't suitable if your symptoms are actually due to a urine infection, which needs treating in its own right. Regular pelvic floor exercises support this process throughout, and losing weight, if you're overweight, can also help.

Medicines

Medicines called anticholinergics (antimuscarinics) or beta-3 agonists can be prescribed if lifestyle changes and bladder training aren't enough. These work in different ways to stop your bladder contracting when it shouldn't, and are usually trialled for around 4 to 6 weeks initially, then continued for several months if helpful, before stopping to see how you manage without them.

Combining medication with bladder training tends to give better, more lasting results than medication alone.

Side effects are common but often mild, most often a dry mouth, along with dry eyes, constipation or blurred vision. Different medicines suit different people, so your doctor may suggest switching if one doesn't agree with you.

Rarely, medication can make it harder to empty your bladder fully, so tell your care team if this happens.

Postmenopausal women may also be offered topical (vaginal) oestrogen, which can improve urgency, frequency and bladder capacity, though this needs caution if you have a history of breast or womb cancer.

Surgical and procedural treatment

If these measures haven't helped enough, and urodynamic testing confirms your bladder muscle is genuinely overactive, several further options exist, usually tried in order of how invasive they are:

• Muscle relaxing injections into the bladder lining: These are done via a small camera passed into the bladder. This calms overactive contractions and helps around half of those treated, but effects wear off after around 9 to 12 months and the injections need repeating. Between 1 in 10 and 1 in 5 people need to learn to pass a small catheter themselves afterwards, since the bladder can become less able to empty on its own
• Sacral nerve stimulation: This is where a small device is implanted near the base of your spine to send electrical signals to the nerves controlling your bladder, similar to a pacemaker. You’ll usually have a trial period first to see whether it helps before a permanent device is fitted
• Peripheral tibial nerve stimulation: This is where a fine needle near your ankle stimulates the same nerve pathway, usually over a series of weekly sessions
• Augmentation cystoplasty: This is a bigger operation that uses a piece of your own bowel to enlarge your bladder. Some people need to self-catheterise afterwards, as the bladder may not empty fully on its own
• Urinary diversion: This reroutes urine away from the bladder into a pouch or bag. This is only considered when other treatments haven’t worked.

When should I see a doctor?

See your GP if urgency, frequency or getting up at night to pass urine is affecting your daily life or sleep, or if you're leaking urine before you can reach the toilet.

Get an earlier or more urgent assessment if you notice blood in your urine, have repeated urine infections, have pain when passing urine, or your symptoms come on suddenly and severely, since these need ruling out as something other than straightforward OAB.