Urinary frequency is defined as “a complaint by a patient who considers that he/she voids too often by day”. Normal voiding is usually going to the bathroom 4-6 times per day, or every 3-4 hours. When someone has to go more frequently than this it can start to take over their life!
There are several things that can contribute to frequency.
Increased sensation in the bladder wall can cause the need to urinate more frequently. Someone with normal bladder sensation will feel a first desire to void at bladder volume of ~300-350 mls and a strong desire to void at ~400 mls whereas someone with increased bladder sensation may feel their strong desire to void at 200-300mls. Bladder sensation may become increased from recurrent urinary tract infections or due to the muscle wall of the bladder being too tight. Some substances such as caffeine also irritate the bladder wall and increase sensation.
A weak pelvic floor can also contribute to frequency. As mentioned previously contracting the pelvic floor muscles fires off a reflex, which relaxes the bladder muscle and suppresses the urge to go to the bathroom. When the pelvic floor is weak and unable to contract strongly the urge will not be suppressed.
Many people can develop frequency just from creating habits of going to the toilet too often. This can start as early as childhood. It also often develops after someone initially suffers from stress urinary incontinence. People with SUI tend to start a pattern of going to the toilet whenever they get the chance to try and keep the bladder empty and avoid leaking. The bladder gets used to voiding often when it is holding only a small amount of urine.
Several other conditions can also be part of the cause including Over-active Bladder (which will be explained further in a separate post), urinary retention when the bladder does not fully empty, and polyuria when the body produces excess urine related to medical conditions or some medications.