The kidneys are constantly making urine. A trickle of urine is constantly passing from the ureters (the tubes from the kidneys to the bladder) down to the bladdee and the amount of urine you make depends on how much you drink, eat and sweat.
The bladder is where the urine is stored. It is made up of muscle and expands like a balloon as it fills with urine. The outlet for urine (the urethra) is normally kept closed. This is helped by the muscles beneath the bladder that surround the urethra (the pelvic floor muscles).
When a certain amount of urine reaches the bladder, you become aware that the bladder is getting full. When you go to the toilet and pass urine, the bladder muscle contracts, and the urethra and pelvic floor muscles relax.
Complex nerve messages are sent between the brain, the bladder, and the pelvic floor muscles to tell you how full your bladder is. These messages also tell the right muscles to contract or relax at the right time.
An overactive bladder is when the bladder contracts suddenly without your control, and when the bladder is not full. The syndrome is a common condition where no cause can be found for the repeated and uncontrolled bladder contractions. (It is not due to a urine infection or an enlarged prostate.)
Overactive bladder syndrome may also be referred to as an irritable bladder or detrusor (bladder muscle) instability.
A study found that about 1 in 6 adults have reported some symptoms of an overactive bladder and roughly 1 in 3 people with an overactive bladder have episodes of urge incontinence.
The bladder muscle seems to become overactive and contract (squeeze) when it should not, but the cause is not fully understood.
Normally, the bladder muscle (detrusor) is relaxed as the bladder gradually fills up. As the bladder gradually stretches, you get a feeling of wanting to pass urine when the bladder is about half full.
Most people can hold easily for some time after this initial feeling until it is convenient to go to the toilet. In people with an overactive bladder, the bladder muscle seems to give incorrect messages to the brain. The bladder may feel fuller than it actually is. The bladder contracts when it is not very full, and not when you want it to. This can result in a sudden urge to go to the toilet. In effect, you have much less control over when your bladder contracts to pass urine.
In most cases, the reason why a bladder becomes overactive is not known. Symptoms may get worse during times of stress. Symptoms may also be made worse by caffeine and by alcohol.
In some cases, symptoms of an overactive bladder develop as a complication of a nerve or brain related disease. Symptoms may be present following a stroke, with multiple sclerosis, Parkinson’s disease or after a spinal cord injury. Also, similar symptoms may occur if you are suffering from a urine infection or a stone in your bladder. These conditions are not classed as overactive bladder syndrome as the causes are known.
General lifestyle measures
The aim is to slowly stretch the bladder over time so that it can hold larger and larger amounts of urine. In time, the bladder muscle should become less overactive and you should become more in control of your bladder. This means that more time can go by between feeling the desire to pass urine, and having to get to a toilet. Leaks of urine should become less likely. A doctor, nurse, or continence advisor will explain how to do bladder training. The advice may include some of the following techniques:
You will need to keep a diary. Make a note in the diary of the times you pass urine, and the amount (volume) that you pass each time. Also make a note of any times that you leak urine (are incontinent). Your doctor or nurse may have some purpose made diary charts to give you. Keep an old measuring jug by the toilet so that you can measure the amount of urine you pass each time you go to the toilet.
When you first start the diary, go to the toilet as you normally would for 2-3 days. This is to get an initial idea of how often you go to the toilet and how much urine you normally pass each time. If you have an overactive bladder you may be going to the toilet once every hour or so, and passing less than 100-200 ml at a time. This will be recorded in the diary.
After 2-3 days, the aim is to then hold on for as long as possible before you go to the toilet. This may seem difficult at first. if you normally go to the toilet every hour, it may seem quite a struggle to last one hour and five minutes between toilet trips. When trying to hold-on, try distracting yourself.
With time, this should become easier as the bladder gets used to holding larger amounts of urine. The idea is to gradually increase the time between going to the toilet and to train your bladder to stretch more easily. It may take several weeks, but the aim is to pass urine only 5-6 times in 24 hours (about every 3-4 hours). Also, each time you pass urine you should pass much more than your initial diary readings. On average, people without an overactive bladder normally pass between 250-350 ml each time they go to the toilet. After several months of training you may find that you just get the normal feelings of needing the toilet, which you can easily deal with for a reasonable time until it is convenient to go.
Whilst doing bladder training, you may only need to fill in the diary for a 24-hour period once every week or so. This way you can record your progress over the months of the training period.
Bladder training can be difficult, but it gets easier with time and perseverance. Bladder training works best if combined with advice and support from a continence advisor, nurse, or doctor. Make sure to drink a normal amount of fluids when you do bladder training.
If there is not enough improvement through bladder training alone, medicines called antimuscarinics (also called anticholinergics) may also help. They include: tolterodine, trospium chloride, oxybutynin, propiverine, and solifenacin. They work by blocking certain nerve impulses to the bladder, which relaxes the bladder muscle thus increasing the bladder capacity.
Medication can improve symptoms in some cases, but not all. The amount of improvement that can be achieved can vary from person to person. You may notice you have fewer toilet trips, less incontinence , and less urgency but it is uncommon for symptoms to vanish completely with medication alone. A common treatment plan is to try a course of medication for a month. If it is helpful, you may be advised to continue for up to six months or so then stop to see how symptoms are when you are off medication. Symptoms may return once the course is finished. Though, if you combine a course of medication with bladder training, the outlook may be better in the long-term and symptoms may be less likely to return when you stop the medication.
These medicines do have their side-effects, but are often minor and tolerable. Always read the information sheet which comes with your medicine for a full list of possible side-effects. The most common side-effect is a dry mouth, and simply having frequent sips of water may counter this. Other common side-effects include dry eyes, blurred vision and constipation. Each medication is different, and you may find that if one medicine causes worrying side-effects, another one may be better suited to you.
Pelvic floor exercises
Many people have a combination of overactive bladder syndrome and stress incontinence. Pelvic floor exercises are the most common treatment for stress incontinence. These exercises aim to strengthen the muscles that wrap underneath the bladder, uterus and rectum.
It is not clear if pelvic floor exercises help if you only have overactive bladder syndrome without stress incontinence. However, pelvic floor exercises may help while doing bladder training.
Treatment with botulinum toxin A
This offers an alternative to surgery if other treatments including bladder training and medication have not helped with your symptoms. The treatment involves injecting botulinum toxin A into the sides of your bladder. This treatment has an effect of calming the abnormal contractions of the bladder. However, it may also subdue normal contractions so that your bladder cannot empty fully. If you have this procedure you will often require a catheter (a small tube) to be inserted into your bladder in order to empty it.
Botulinum toxin A has not been approved for the treatment of overactive bladder syndrome in the UK. Make sure that you discuss this procedure fully with your doctor and understand all of the risks and benefits before you go ahead with it.
Overactive Bladder Surgery
If the above treatments are unsuccessful, surgery is sometimes suggested to treat overactive bladder syndrome. Some procedures include: