Excuse the rather indelicate question, but I was wondering why sometimes you can be desperate to pee and then when you go, you’re done in 10 or 15 seconds, while other times, despite there being less of an urge, you can let fly like a carthorse for three times that long and produce maybe a pint?
How can your bladder feel like it’s bursting, when on other occasions it’s clearly holding far more without a problem?
For me, its usually more proportional to the time in which I’ve held it. After sleeping 8 hours without peeing, my whole belly sometimes hurts, yet I only pee for a few seconds.
The answer lies in the amazing smooth muscle fibers in the bladder. Smooth muscle is different from the more common skeletal muscles that move you around and cardiac muscle that beat your heart. Smooth muscle is not an effective contractor, but it can stretch really well.
The urge to pee begins when the bladder starts to stretch. In normal functioning adults the urge can be ignored at first if it’s not convenient to urinate. There is a cycle of urge and ignore that occurs every 60-90minutes (IIRC) at first, but becomes stronger and more frequent as bladder volume increases.
The contractility of smooth muscle, like I mentioned above, isn’t very efficient. This is why, when you have a large volume of urine, you may notice that you will begin to urinate again when you think you’re about done (a la Austin Powers). There is also a point at which the bladder can be stretched too far and be unable to contract at all! You do not want to reach that point.
First, there are several different mechanisms that cause urinary urgency. They can be different in men and women.
Prostate enlargement can cause urgency, with small urine output is common, in older men, but can be seen in men as young as early 20s.
Prostate enlargement can be due to infection, BPH (Benign Porstatic Hyperplasia/hypertophy) or prostate cancer. Only a doctor can tell you which could be causing the problem.
Diabetes can cause nerve damage to the bladder. Often, the bladder dosen’t fully empty on the first try.
Interstitial cystitis can be seen in either sex, but is more common in women. It causes urgency and can cause incontience.
Hope this helps.
Can the “urge” be related to the concentration (color) of urine at all, or is that purely my imagination?
USCDiver, could you tell us more about that “urge/ignore cycle”? Is that like when you have to pee and you ignore it and it goes away? Because when I was a kid, I could ignore it and it would go away, and now that I’m not a kid anymore it isn’t so easy.
Yes and no. Sometimes darker urine is caused by a less diluted mix, and that might cause a burning sensation if a drop leaks into the urethra. However, a big dose of vitamins will usually cause dark urine. Sometimes, a heavy workout or motocross riding will produce blood in the urine, temporarily.
In a similar thread a while back, a test lab tech told us he had seen thousands of samples, and the color had no correlation to the health of the patient.
As picunurse said, and my own experience has shown, BPH (swollen prostate) can cause an urgent need to pee. However, the prostate squeezes on the tube, and the bladder cannot be emptied. So, a fella can walk into the restroom doing the pee-pee dance, and urgently let out 400ml. The flow stops, the urgency and pain are gone, but he walks out with half a liter still sloshing around in the bladder.
My high-school Biology teacher told us that the chemical reaction that produces the “gotta pee” sensation is one of the most complicated chemcial reaction in the body.
Was he right or is that just something else I should forget about high school?