Overactive Bladder (OAB)

An overactive bladder can be a condition in its own right, caused by increased sensation from small volumes of urine in the bladder.⁴ This may cause unwanted contractions of the detrusor muscle (smooth muscle fibres that form the wall of the bladder)⁵ before the bladder is full, leading to a frequent need to urinate.⁴

But OAB may instead be a symptom of an underlying condition, such as:

• Diabetes (high blood-sugar levels).⁴
• A urinary tract infection (UTI) or other bladder disease.⁴
• Pressure on the bladder caused by an ovarian cyst (a fluid-filled sac inside the ovary).⁶
• Pressure on the bladder caused by an enlarged or swollen uterus.⁴
• Extra body weight, which can put pressure on the bladder.³
• An ulcer or growth in the bladder.⁴
• Neurological (nervous system) disease.⁴
• Pelvic organ prolapse, where the loss of muscle support can lead to the uterus or vagina “slipping”.⁴
• Low levels of oestrogen hormones after menopause.⁷

Pregnancy, post childbirth, older age, and high body mass index (BMI) are all strongly associated with having an OAB.^9,10

OAB is characterised by an urgent and frequent need to urinate.⁴ Patients will have to rush to the toilet often during the day and will wake up needing to urinate at night.⁴ These symptoms are often accompanied by urinary incontinence (leaking of urine).⁴

The symptoms of OAB can be worsened by habits that can irritate the bladder, such as smoking, or drinking caffeine, fizzy drinks or alcohol.⁴

There are several different tests that can be used to diagnose an overactive bladder and any potential underlying problems. These include:

Frequency volume chart: A ‘bladder diary’ where the patient records the following for their Health Care Practitioner (HCP):^4,1

• The amount of fluid they drink.
• The types of fluid they drink.
• How often they need to urinate.
• The amount of urine they pass.
• Any leakage that takes place.
• How often they experience an urgent need to urinate.

Physical examination: Over and above a general physical examination, the HCP may examine the pelvic area, vagina and rectum.¹¹

Urinalysis: A urine sample is collected and tested with a dipstick to check for signs of infection.¹² This can be done by a primary HCP (doctor or nurse).

Ultrasound: This non-invasive imaging test to scan the bladder using sound waves, can provide a detailed look at what is going on inside the abdomen and bladder.^13,14 Ultrasound scans can detect bladder stones, tumours and issues affecting the bladder wall.¹⁴

Computed tomography (CT) scan: Another type of non-invasive imaging test, which combines X-rays with computer technology to create three-dimensional images of the bladder.¹⁴ CT scans can detect obstructions, infections, cysts, tumours and injuries.¹⁴

Cystoscopy: A bladder examination via the urethra, usually done by a urologist using an instrument called a cystoscope.¹⁵

Urodynamic testing: A series of tests done by a urologist or trained technician to measure how much urine remains in the bladder after voiding, the urine flow rate/speed and levels of pressure on the bladder as it fills up.¹⁶ It can be done in the urologist’s office or at a hospital.¹⁶

• Urine remaining in the bladder: The amount of leftover urine (known as postvoid residual urine) can be scanned using ultrasound and drained for measurement using a thin tube called a catheter.¹⁶
• Urine flow rate: Urinating into a device called a uroflowmeter measures how much urine is in the bladder and how fast it comes out.¹⁶
• Bladder pressure: This is done using a cystometry test, where the bladder is emptied using a catheter and then slowly filled with fluid using another catheter.¹⁶ A sensor in the rectum or vagina is used to measure the pressure on the bladder.¹⁶ This measures how much liquid the bladder can hold, how much pressure builds as it fills up, and how full it is when the need to urinate starts.¹⁶

The symptoms of OAB are distressing to patients, affecting their daily activities, sleep, sexual function and overall mental health.^1,2,17 Women who suffer from OAB often experience anxiety, depression and isolation.^4,17

There are numerous ways to treat OAB, depending on its cause and severity:

• Medications called anticholinergics are used to treat urinary urges and an overactive bladder muscle.¹⁸
• For menopausal and postmenopausal women, oestrogen therapy with vaginal gels or creams can help to improve the symptoms of OAB.¹⁹
• Special exercises, like pelvic floor muscle training (PFMT), can reduce the symptoms of OAB and improve quality of life for patients.²⁰
• Bladder training, sometimes with the guidance of a physiotherapist, can help the bladder adjust to holding larger volumes of urine for a longer time.⁴ The trigger to urinate can be suppressed by tightening the pelvic floor muscles.⁴

In serious cases of OAB, surgery might be needed.⁴ Types of surgeries include:

• Botulinum toxin (Botox) injection: The bladder wall is injected to relax the muscle.^4,21
• Percutaneous tibial nerve stimulation (PTNS): An electrode or implantable device is inserted behind the ankle to stimulate the nerve there The tibial nerve and bladder nerves share a common pathway in the sacral plexus at the base of the spine. Stimulation of the tibial nerve sends messages via the bladder nerves to make the bladder relax.^4,22
• Sacral neuromodulation: A special transmitter is used to send electrical impulses to the sacral working on the nerve pathways to help restore proper bladder function.²³
• Augmentation cystoplasty: A piece of the bowel is removed and added to the bladder to make it larger and increase its ability to hold urine.²⁴

Lifestyle/behavioural changes can help with the symptoms of OAB:

• Drink enough fluid, to prevent bladder irritation from concentrated (strong) urine ⁴
• Avoid excessive drinking, to reduce bladder fullness and the urge to urinate.⁴
• Avoid fizzy and acidic drinks, caffeine and alcohol, to reduce bladder irritation.⁴
• Quit smoking.⁴
• Maintain a healthy weight.^10,11

Usually, a combination of therapies works to improve treatment effectiveness and patient quality of life.²⁵ Psychological support, like counselling, is also important for patients dealing with the struggles of OAB.²⁵

*Smooth muscle fibres that form the wall of the bladder.⁸