Hi. I am 15 years-old and whenever I have an erection and I pee afterwards, my penis starts to have this stinging pain. This is the same when I wait too long to pee. Why does this happen?
If you have pain when you urinate all the time or even most of the time, then it is a sign that you have an infection. But since you are only feeling discomfort at specific times, the cause is likely to be something else.
Inside your pelvis you have a number of organs that are related to your ability to have erections and ejaculate. One of those is the prostate gland, which most people hear about in relationship to old men having prostate problems. It is located just under the bladder Among the prosate's many functions, it contains muscles that control the flow of fluids through the urethra. If you look at the drawing, you will see a "y" shaped path through the prostate. Only one branch of each fork is open at at time. The muscles in the prostate serve as a switching mechanism. In a normal mode, urine is allowed to flow from the bladder and the passage to the ejaculatory duct is closed off. When a man is sexually aroused, the passage to the bladder is closed off and the passage to the ejaculatory duct is opened. Because of this, a man is not able to urinate when he is sexually aroused.
What I think is happening to you is that when you have an erection, the path to the bladder is squeezed shut. Even after the erection fades, the prostate hasn't fully relaxed its grip on the tube to your bladder. When you urinate, the pressure is forcing the muscles open, which is not comfortable.
The same thing happens when you are holding back from urinating. You tighten your muscles to keep urine from escaping and your prostate clamps down to help. But when you rush in to actually pee, the prostate doesn't have a chance to release completely before the pressure of the urine forces it open.
What you can do is when you need to urinate shortly after an erection, concentrate on relaxing so the urine at first just flows out instead of rushing out by squeezing your bladder muscles. This will give the prostate a chance to get out of the way. You can try to do the same when you've been holding off urinating too long, but that will be harder to do. Once the flow is steady, you can then squeeze to empty the bladder.