To pee or not to pee is NOT a philosophical question but a troublesome one that one in four older adults in the UK asks themselves every day. Overactive bladder – a state when one has to urgently visit the toilet more than eight times a day – is a very common problem in the ageing population and that’s why I spent the last four years studying mechanisms of urinary bladder function and dysfunction.
Urinary bladder is a muscular football which sits inside your tummy. Healthy people only think about the bladder when it is so full that the pressure inside the bladder reaches a threshold. Then, we become aware for the first time that we will have to pee soon. Research has shown that from there you have roughly an hour before you will absolutely need to pee. We only pee a few minutes a day so what is the bladder doing the rest of the time? A lot!
Its main activity is to store urine. Storage doesn’t sound exciting at first, yet I spent years researching just that – how the bladder stores urine. There is nothing static about the bladder storage mode – it is all wobbly and performs very dance-like movements! As the urine comes down from the kidneys via ureters the volume of urine inside the bladder increases. The football gets bigger and bigger during the time between toilet visits. The increase in size is what looks like a dance.
I focused my efforts on understanding how the healthy bladder works and what makes it overactive. To pee, the bladder smooth muscle needs to contract simultaneously forcing the urine out. Not to pee… muscles in the bladder need to allow increasing volumes of urine to accumulate inside. It does so by being compliant – agreeing to relax slightly to keep the pressure in the bladder below the peeing threshold. As the bladder football is made up of patches, it is those patches that relax and contract in order to keep the bladder quiet, below the ‘to pee’ threshold.
The small movements on the bladder football patches are called micromotions. I observed how the bladder football works by filming its surface and analysing the micromotions on the bladder wall. It is fascinating to see that the process of urine storage is very much like a dance, with different parts of the dancing football moving and relaxing in order to keep the bladder sensation below the pee signal threshold.
Scientists have already shown that those microcontractions on the bladder football surface are part of the normal functioning of the bladder, and that they change with age and in disease. It is important to understand how they work because patients with overactive bladder syndrome have more microcontractions dancing activity than healthy people. As overactive bladder is a growing problem in ageing societies, we need to find new ways to prevent and treat it. If we explain how those small contractions are generated and controlled we can change them. This could, before we get older, answer the ‘to pee or not to pee’ question.
About the Author
Dominika Bijoś completed her PhD on lower urinary tract physiology at the University of Bristol, UK. She previously studied Biotechnology at University of Perugia, Italy. She is currently investigating the possible therapeutic use of Viagra on bladder contractility. She organises a European annual conference for early career researchers working in functional urology and enjoys mentoring and coaching. In her free time she enjoys science communication and discovering beautiful places in London, UK, Europe and the World.