Why do some people urinate when they are afraid or ...

I think that when people are afraid some of there muscles get  loosed so much  till they can't control of their blister. but I will be glad if someone give us a better explanation.

You are right! Fear creates a spasm and blocks control from the head, this leads to a spontaneous release urine.

You know that feeling you get when something really scary happens; like a possible car accident? You start sweating, you fell jittery, your heart pounds, you breath heavier and you feel that tingling through your body? That's called a sudden adrenaline rush. Your body has a built-in "fight-or-flight" mechanism, that occurs in response to a scary or startling situation. What it means is that all your body systems speed up in response to fear. They call it "fight-or-flight, because your body is ready for however you decide to deal with that situation. You'll either fight or run (flight). Just like when you see a bar fight about to happen. The two opponents will be shaking, moving around, breathing heavy, etc. They are pumped up (on adrenaline). If someone with even a slightly weak bladder is faced with intense fear, because everything is sped up, urine can leak out. This answer is from a medical stand point. I hope i did'nt get too indepth to answer your question.

Duirng childhood we wet the bed. And because most mother's are stupid they yell at the oftening child making them worse. All thier life they associtate fear and urinating. To make things even worse we hit putery where we are faced with many penile ejacualtons. This time its our girlfriends who scare us for ejaculating. Agan we associate whatever comes out of that little guy is bad and we are terrified of the consequences.