Firstly a Few Facts

There are two types of muscles in your body :

Skeletal muscle – we have control of these and can make them contract and relax as we wish. These are the moving muscles like the biceps and hamstrings.
Smooth muscle – we don’t have control of these muscles , they contract by themselves, automatically and are controlled by our brain. They are the 'function' muscles that keep the body working e.g the heart and the gut. They work by stretch response. For example, as blood fills the heart chambers (input) the walls stretch and at a certain point of stretch automatically contract to push the blood out (cardiac output). The same with the gut – as the food bolus passes through, it stretches and squeezes and pushes it along a bit like an inchworm!

Your bladder is quite unique – it is made of smooth muscle, just as your gut and heart are, but you have conscious control of it.

So, as your bladder with its outer layer of smooth muscle fills if it followed the laws of smooth muscle it would contract right?
Well in fact it doesn’t behave like the other smooth muscles in the body – yes it stretches as it fills, but instead of automatically contracting it actually RELAXES as it fills and this is where your conscious level of control comes in. You get background signals that things are filling up down there but you are able to put it off until an appropriate time …in other words you can hang on !

Once it fills to capacity, (the average is about 300-500mls which = 1-2 cups)  you may reach the point of a strong desire to void or wee. Some people call this“busting” which won’t actually happen by the way! If no loo or appropriate option to empty is available you can still dampen the sensation at this point and the bladder will continue to fill and store the urine until you do have the chance to go (think sitting in a traffic jam , or a meeting that has gone overtime)

However, the sensation that you need to go should be a feeling of fullness above the pubic bone - where you bladder sits, and swells up as it fills. If the sensation is one of  'gotta go now' in the urethra ( the tube you urinate through) then your bladder is taking charge, not listening to your signals to stay relaxed and has contracted, forcing urine into the neck of the bladder which in turn triggers the micturition reflex ie you wee!

As the bladder fills, the bladder walls should stay relaxed, the pressure should remain low inside the bladder and high in the urethra which is sealed closed by several mechanisms - one being the pressure of the urethral sphincter ( like a washer inside a tap) and the pelvic floor muscles which will tighten to help you consciously 'hold on'.

When you urinate the pelvic floor relaxes, the pressure drops and the bladder contracts which creates high pressure in the bladder. Urine flows from the area of high pressure , the bladder, to the region of low pressure, the urethra and therefore empties.

So now that we know how the bladder actually works, let's bust  I totally meant that pun) a few myths about bladder behaviour:

Bladder Myths

You have to go when you first feel the urge

BUSTED: as you have read – the bladder can stretch to an average capacity, in times of need it can stretch to hold up to 800 - 1000mls although it is just as wise not to let things go too long as you shouldn't allow the bladder to overstretch too far as it cna become become floppy and unable to contract properly. 
A regular 2 cup hold is healthy. If you suffer from frequency and urgency your bladder capacity will be much less and you will need to firstly see your doctor to make sure there is not another cause such as a urinary tract infection before undergoing bladder training under the guidance of a medical professional (such as a women’s or men’s health physiotherapist)

I have to go “just in case” before going out.

BUSTED: Unless your bladder is actually full , you DO NOT need to go just in case. If you are a “just in case” person, then chances are you know where every loo in your area is! There will be a loo at the shopping centre, the gym, work or your friends house so wait until you actually need to go!

If I drink more, I will wee more and might leak so I drink less to avoid accidents.

BUSTED: In fact, the less you drink, the more concentrated your urine becomes, this will irritate your bladder and make you want to go more- and so the urgency/frequency round-about continues.

All the books say drink 8 glasses of water a day.

BUSTED: What size glass? 8 x small ones or 8 x large ones …how many different glass sizes in YOUR cupboard? The general rule of thumb is that you drink enough to remain hydrated. Signs of early dehydration are thirst and darker urine. So keep an eye on the colour of your wee- the first one of the day will be concentrated but from then on they should be pale or nearly colourless, not like a glass of beer or apple juice. If you sweat a lot, you need to increase your fluid intake as well. The exception is if you are on a fluid restriction from your doctor in which case you should continue to be guided by them.
If unsure – speak to your doctor !

I don’t need to drink water – I get it from my coffeee

BUSTED: Any drink containing caffeine acts as a diuretic  i.e. it increases urine production or in other words, can make you wee more. It can irritate your bladder and increase urgency and frequencyYou can  count caffeine drinks in your daily fluid amount but be aware that it may be contributing to your bladder woes. At least balance it with a glass of water. If you suffer from urgency or frequency you need to look at your caffeine intake – keep a diary for a few days and be honest with yourself about how much caffeine you are drinking and whether you notice the sudden urge to go after drinking a coffee, tea or coke. Some people find that caffeinated drinks don't affect their bladder at all but it certainly helps to limit them to see if they do.

Here’s to a healthy bladder !

The material presented here is intended as an information source only. The information is provided solely on the basis that readers will be responsible for making their own assessment of the matters presented herein and are advised to verify all relevant representations, statements and information. The information should not be considered complete and should not be used in place of the advice of a health care provider. Pelvic Floor Exercise does not accept liability to any person for the information or advice provided , or for loss or damages incurred as a result of reliance upon the material contained herein.

© Fiona Rogers, Pelvic Floor Exercise all rights reserved