[DoctorTan]

Urinary frequency aka always feeling the urge to pee is indicative of a problem in the urinary bladder.

The urinary bladder is basically a muscular bag that sits deep down in our pelvis. 2 tubes (ureters) stick into it from the top on either side. These tubes bring urine from the kidneys down into the bladder. One tube (urethra) sticks out through the bottom. This tube brings urine out into the world. Along the way, it goes through the prostate and the penis for guys and basically nothing for women.

At the base (floor) of the bladder, there is a very sensitive roughly triangular patch called the trigone. When there is pressure on this patch, it sends signals to our brain to tell us we need to pee. When we reach the toilet, the brain sends signals down to the bladder to squeeze and at the same time relax the sphincter muscles at the urethra (the valve) and this pushes urine out of the bladder. Usually it takes about 300ml of urine to exert enough pressure on the trigone to give us the sensation that we need to pee.

OK, so now we understand this, it is easy to understand the causes of frequent urination.

1. Urine Tract Infection or to be more precise bladder infection (cystitis)
Inflammation of the bladder wall causes it to be very irritable and squeeze more and also inflammation of the trigone area will make it send signals to the brain to say the bladder is full when it is not. This also explains why STDs which usually only infect the urethra and not the bladder do NOT usually cause urinary frequency. Sometimes bladder inflammation is not caused by infections but by other diseases eg interstitial cystitis.

2. Nerve problems like Diabetes or stroke or overactive bladder syndrome. This sends wrong signals to the bladder to squeeze thus putting pressure on the trigone even when the bladder is not completely full.

3. Prostate Enlargement. This can cause obstruction to urine outflow. The bladder then has to squeeze stronger to push urine out. The walls of the bladder become stronger and more irritable. Such that it squeezes even when the bladder is not full.

4. Stones. Stones can be a nidus for bacteria thus causing cystitis which causes urinary frequency. Stones can also sit on the trigone which causes the trigone to misinterpret the weight of the stone as pressure from a full bladder thus sending signals to the brain to tell you that you need to wee.

5. Bladder cancer. This can cause urinary frequency via bladder inflammation.

6. Or maybe you really do need to go to the toilet very often. This is caused by diseases that cause you to make a lot of urine like Diabetes or if you are taking medicines that make you pee a lot (diuretics).