Overactive Bladder: Symptoms, Causes and Treatments

Overactive bladder (OAB), also sometimes referred to as an ‘irritable’ or ‘sensitive’ bladder", is defined by an ongoing increase in urinary urgency, which can include waking during the night with an urgent need to pass urine – with or without incontinence – in the absence of infection or another explanation. 

Of the four symptoms that define overactive bladder, urinary urgency is generally the most impactful to patients. Doctors separate ‘urge’, the normal sensation to pass urine when the bladder is nearly full, with ‘urgency’, a desperate need to pass urine that cannot be ignored. Patients with overactive bladder have many episodes a day of feeling a desperate need to pass urine.

As well as urgency, overactive bladder is defined by increased frequency during the day and waking during the night to pass urine – a condition known as Nocturia, which doesn’t involve bedwetting. 

According to the NHS, it's normal to go to the toilet between four and eight times a day, and once in the night. Any more than this could indicate an overactive or irritable bladder.

The condition is more common among older adults and affects both women and men.

“In many cases, we simply don’t know what causes overactive bladder in men or women,” says Professor John S. Young, Translational Healthcare Lead, Centre for Biodiscovery. Professor Young goes on to explain:

The bladder is a hollow organ that looks a little like a small balloon. The walls of the balloon are made of muscle, called the ‘detrusor’ muscle. The bladder grows to accommodate urine produced by our kidneys and during this process, the muscle relaxes, allowing the bladder to increase in size. When we pass urine, the muscle contracts to squeeze urine out of the bladder. 

In terms of overactive bladder, it used to be thought that the muscle of the bladder would squeeze when it’s not necessary – something called ‘detrusor overactivity’. In the early 2000s, it was shown that detrusor overactivity does not relate especially well with overactive bladder symptoms, and we still don’t fully understand if there’s any relationship.

There are lots of theories about the causes of overactive bladder but, in most cases, it is unclear. An exception – in about 1 in 20 cases – is when overactive bladder occurs because of another medical condition.

Overactive bladder syndrome can be the result of an underlying disease or condition.

An obstruction to the urethra (the tube through which urine leaves the body). In men this is often caused by an enlarged prostate. The prostate is a gland in men, which is located at the base of the bladder. The prostate produces a fluid at the point of ejaculation. Often in older men, the gland starts to grow larger and can obstruct the urine tube. A symptom of this is a poor stream of urine, also known as problems emptying the bladder or incomplete emptying of the bladder.

Conditions that affect the nervous system - such as spina bifida, multiple Sclerosis and Parkinson's – can result in overactive bladder.

Many other diseases or conditions can produce similar symptoms, and this can make it difficult to diagnose and treat overactive bladder.

An overactive bladder at night, also known as nocturia, is a common problem, particularly as you age. One in three adults over the age of 30 need to make at least two trips to the bathroom at night.

People experiencing nocturia wake up more than once a night to go to the toilet, where most people can sleep six to eight hours without having to get up. Waking to pass urine can result in sleep loss along with other complications, as your normal sleep cycle is disrupted. 

If a patient is experiencing nocturia alone, their doctor will check for this and the treatment will be quite different to if the patient is experiencing nocturia as part of OAB symptoms.

Urinary incontinence affects twice as many women as men. The two most common types being stress incontinence and overactive bladder. This is because certain life events such as pregnancy, childbirth and menopause can cause problems with the muscles and nerves that help the bladder to hold or pass urine. 

44% of women say they’d feel embarrassed by developing incontinence, while feeling less attractive and more self-conscious were the next most common answers in TENA’s Age of Confidence Survey. But this needn’t be the case. Read on to learn more about overactive bladder treatments that are available.

Many cases of overactive bladder in men are caused by an enlarged prostate. The prostate may get larger with age and block the flow of urine, causing overactive bladder symptoms. However, there are numerous other factors that may be contributing to symptoms, other than prostate problems, such as lifestyle and bladder stones, along with more serious conditions that affect the nervous system.