How does urinary incontinence occur?

Urinary incontinence is defined as a loss of the ability to consciously retain urine and of deciding for oneself the time at which it is emptied. The control of urination - the Latin term for this process is "micturition" - requires a complicated regulatory mechanism, which controls the interplay between the urinary bladder, the sphincter system located at the exit of the urethra and the nervous system.

The urinary bladder has the job of storing and expelling urine. During the storage phase, the bladder fills without us being consciously aware of this, with the elastic bladder wall musculature, known as the detrusor muscle, allowing filling to take place without any pressure increase. The sphincter system at the exit of the urethra is closed during the filling phase.

As the bladder becomes increasingly full, the nerve impulses from the bladder, which travel along nerve paths in the spinal cord to the micturition center in the brain stem and from there to higher brain centers, grow stronger. Once these impulses have reached a certain strength, we perceive them as an urge micturition.

Now, we have the ability to control the micturition center with our cerebrum, an ability that is learned in childhood. If the place and time are right, we can voluntarily induce urination. In response to the relevant "commands", the bladder contracts and expels the urine. During the emptying phase, the sphincter at the exit of the urethra is lost of tone and open. However, control via the micturition center also allows us to suppress the urge micturition or to initiate urination even in the absence of an urge micturition.

This simplified explanation of urination makes it obvious just how susceptible to impairment the process can be. An uncontrollable loss of urine can occur when, for example:

• The sphincter system is not strong enough and so does not close properly,
• the bladder contracts too much or not at all,
• there is an obstruction below the bladder or the neural process for transmitting of impulses between the bladder, spinal cord and brain is either totally or partially impaired.

All these functional disorders are in turn triggered by the most diverse causes, for example, by urinary tract infections, loss of tone of the pelvic floor muscles, benign prostatic hypertrophy, degenerative changes in the brain, metabolic diseases, spinal cord injuries, effects of medication, etc.

Urinary incontinence is thus really a "symptom", that means a sign of an underlying disease that needs treatment. This is why the assumption that urinary incontinence is no danger for health is wrong. It is always important to establish the cause!