Causes of and preventable risk factors for overactive bladder

Despite living in an age where we publish every detail of our life, we still don’t seem to be able speak freely about all aspects of our health. Indeed, the extent of open discussions about our “waterworks” consists of adverts showing vibrant, mature women out on the town wearing discreet incontinence underwear, and the occasional information poster with a cross-legged stick figure lurking on the back door of a motorway rest stop bathroom.

And yet, bladder issues are not uncommon. On average about 16% of people with vulvas develop overactive bladder (OAB) symptoms in their lifetime, with the incidence increasing with age.¹ OAB is a condition characterised by urgency, frequency, and nocturia. That is; the feeling that when you need to wee you have to go right now and cannot wait regardless of how full your bladder actually is (urgency), needing to go to the toilet to urinate more than 7 times per day (frequency), and waking up more than once at night to pass water (nocturia). These symptoms can occur with or without accidental leakage (incontinence).²

However, it is important to know that it isn’t considered a normal part of ageing that you just have to live with, and if you do experience any of these symptoms you should speak to your doctor.

With an overactive bladder, your detrusor muscle contracts too often and unpredictably before the bladder is full

In a normally functioning bladder, the organ fills with urine like an expanding balloon. This urine is kept in the bladder by a sort of gate called the urethral sphincter. In simplistic terms, think of it like the rubber knot of your water balloon. For added security, the gate has back up from your pelvic floor muscles — a hammock-like sling that can tighten around the sphincter when pressure in the area goes up, such as when you cough. This tightening avoids leakage of urine in most situations.

Eventually, your bladder fills up enough and starts sending signals to your brain that you need to go to the bathroom. However, at this point, you are still able to voluntarily control whether you empty your bladder or not. Once you are able to make time to go to the bathroom, your brain signals both the urethral sphincter and pelvic floor muscles to relax, and prompts another muscle that makes up the bladder, the detrusor muscle, to contract, squeezing urine out of your bladder.

As the name suggests, with an overactive bladder your detrusor muscle contracts too often and unpredictably before the bladder is full. The detrusor muscle is a type of muscle known as “smooth muscle”. Unlike your external urethral sphincter, smooth muscle isn’t under voluntary control. You cannot make a conscious decision to contract or relax it.

You may feel the need to go to the bathroom often and only pass small amounts of urine

When your detrusor muscle is overactive you may feel the need to go to the bathroom often and only pass small amounts of urine, leak because you have a sudden uncontrollable urge to empty your bladder and can’t make it to a bathroom in time, and you may get up two or more times at night to go to the bathroom.

If you have these symptoms you may be wondering why you developed them. And if you don’t, you may be thinking that it would be great to know how to prevent them from occurring in the first place. Sometimes it’s just the luck of the draw, but there are a few known predisposing factors.

Things that feel like OAB but aren’t

One of the most common and easily treatable causes of overactive bladder symptoms is a urinary tract infection. This isn’t a long-term problem, although it can often go undiagnosed and feel chronic. The key differentiating factor is that bugs in your wee can cause painful urination (dysuria).³

While they are there, they irritate and inflame the bladder, causing over-activity. Urinary tract infections can be identified if you give your doctor a urine sample, and are often easily treated with a course of antibiotics. Drinking plenty of water helps to flush out infections, and simple hygiene measures like wiping from front-to-back after you go to the bathroom can help keep contaminating bacteria from your back passage away from the opening tract of the bladder (urethra).

Bladder stones can also cause obstruction of the flow of urine, resulting in an overactive bladder

Another easily treatable cause of overactive bladder symptoms can be a medication review. Some medications increase your urine output, and having your doctor review these can resolve your overactive symptoms.

Though very rare, your doctor will always rule out a bladder tumour. The most common presenting complaint for bladder tumours is frank (obvious, visible) blood in the urine. If you find this, you should see your doctor urgently. According to figures by Cancer Research UK, around 2,800 people with vulvas will get bladder cancer each year.⁴ This makes up about 3% of all cancer cases.⁵

Stones can also cause inflammation, irritation, and obstruction of the flow of urine resulting in an overactive bladder. When stones form anywhere in the upper urinary tract, this is known as “urolithiasis”.⁶ Bladder stones usually form when your bladder doesn’t completely empty its urine stores.⁷ Stones can present with pain in your side or back, that radiates towards your groin in waves, along with blood-stained urine. Drinking plenty of water has been shown to reduce the risk of stone formation.⁸ Depending on the composition of the stones your body forms, various dietary changes can also be beneficial.

Genuine OAB causes and how to prevent them

Lifestyle

As is the case with most medical advice, there is no magic bullet to preventing OAB, but simple healthy lifestyle choices can go a long way.

Being overweight contributes to the development of OAB by increasing intra-abdominal pressure,⁹ putting a strain on the pelvic sling muscles, and stretching the nerves to pelvic organs such as the bladder. Certain exercises can be more helpful than others here. Try to focus on activities that don’t increase pressure on your pelvic floor (heavy weight lifting, stomach crunches) and instead work to gently improve your core muscles (e.g. pilates).

Smoking can also result in an overactive bladder by weakening the pelvic floor muscles through chronic coughing

Smoking can also result in an overactive bladder by weakening the pelvic floor muscles through chronic coughing, predisposing you to the development of bladder tumours, and acting directly as a bladder irritant.¹⁰ Caffeine is a potent bladder irritant as well, and reducing your tea and coffee intake can improve your symptoms. The same holds true for acidic fruit juices and sugary carbonated drinks. Alcohol is both a bladder irritant and a diuretic — a substance that makes you pass more urine. Thus, reducing your alcohol consumption can improve your quality of life and reduce overactive bladder symptoms.

Chronic constipation is a surprising instigator of overactive bladder, because long-term straining can damage the pelvic floor muscles.¹¹ Avoid this by eating a varied diet high in fibre and staying well hydrated.

Prolapse

Prolapse of a pelvic organ (bladder — cystocoele, bowel — rectocoele, womb — uterine prolapse) can result in OAB. As the sling muscles weaken and the organ prolapses into the vagina, muscles and nerves are stretched. It can also result in “kinks” in the outflow of urine from the bladder, stopping it from emptying completely. This often occurs in people who have given birth. It can be prevented in the first instance by performing Kegel’s exercises to strengthen the pelvic floor. Your doctor or midwife can refer you to a physiotherapist for instruction.

If you do have prolapse, there are devices such as ring or gel horn pessaries that your gynaecologist can insert into the vagina. These are soft and fairly comfortable and they work much like tent poles, suspending a lax wall and giving it support. In people who are postmenopausal, administration of a low dose oestrogen dispersed through the vagina may be helpful.¹² Oestrogen is involved in the strength and elasticity of tissues which can become lax through menopause. Additionally, the bladder neck and outflow tract contain a high concentration of oestrogen receptors which are no longer stimulated during menopause. This results in more urinary tract infections and irritable voiding patterns.¹³

Medical conditions

Certain medical conditions affecting the nervous system are implicated in the development of overactive bladder, such as multiple sclerosis (MS), diabetes, stroke, Parkinson’s, and infections/trauma/defects in the spinal cord. When nerves are affected, you can have issues with both the storage and emptying of urine through a variety of different mechanisms. Sometimes, as in the case of a diabetic neurogenic bladder, you initially go to the bathroom less. Over time this results in the bladder muscle getting stretched out of shape and losing its tone. Once that occurs, the detrusor muscle can become unstable or overactive.

You don’t just have to put up with it. Basic interventions can prevent or reduce any symptoms that you have

For people with MS, nerve pathways can be interrupted leading to involuntary contractions of the detrusor muscle. Alternatively, these interrupted nerve pathways can work together in an un-coordinate fashion, meaning that you have poor flow and the bladder does not empty completely when you go to the bathroom. The volume of urine that remains then stimulates further detrusor muscle contractions, making you feel as though you need to go again in a short space of time.

Chronic incomplete bladder emptying can lead to an overactive bladder outside of the picture of neurological disorders. People who suffer from dementia can often experience overactive bladder for a variety of reasons related to self-care and cognition.

While there may be several contributing factors towards issues you may be experiencing with your bladder, there are two important take home messages. Firstly – that you don’t just have to put up with it, and secondly – that basic interventions can prevent or reduce any symptoms that you have. If you find you are experiencing OAB symptoms then you should visit your doctor who will be able to rule out any conditions that could be causing the symptoms and advise you on how to proceed.

Featured image is of a roll of toilet paper lying on its side, slightly unrolled as if it’s about to be used. The toilet roll is against a pale yellow background

Last updated October 2022
Next update due 2025

Disclaimer: This content is designed to provide general information and is not a substitute for medical advice. Medical opinion, practice and routine may vary from country to country and may change from time to time. The author is not liable for the results of misuse or inappropriate application of the information. If you are an individual who chooses to access this information, you should not rely on the information as professional medical advice or use it to replace any relationship with your doctor or other qualified healthcare or social care professional. For medical concerns, including decisions about medications and other treatments, individuals should always consult their doctor or, in serious cases, seek immediate assistance from emergency personnel. Individuals with any type of medical condition are specifically cautioned to seek professional medical advice before beginning any sort of health treatment. Individuals with specific queries or concerns should seek appropriately qualified medical advice. Clinicians must use their own judgement when interpreting this information and deciding how best to apply it to the treatment of patients.