Why Do People Shudder After Peeing (Pee Shivers) and Why Do Some People Not Shudder?
The pee shivers have been a plague upon our houses for the entire span of human life, probably other life too. Few can resist the urge to shudder after the completion of a session of yellowing the toilet water. Many have asked the same question you have asked, what are the pee shivers and where do they come form, few have answered, but enough have answered for me to give you a solid response.
One theory is that the autonomic nervous system (ANS) is the cause. When you have to pee you hold it in, the longer you wait the tougher it is to hold in. You ANS is sending the signals to your bladder and urethral sphincter to hold that pee in at all costs, when you finally do pee, your ANS allows the relaxation of the urethral sphincter and the flow to begin. This switch in the ANS is thought to be the cause of the shudder or pee shiver. The longer you hold it in the greater the pee shiver will be.
If you don’t like that explanation there is a theory that is much easier to explain and understand. When you pee you are expelling a fairly worm liquid. A regular shiveris the body trying to keep warm, perhaps the loss of a little hot water bottle causes a drop in body temperature and thus a shiver is produced to recover some of that lost heat. That doesn’t quite explain why you still shudder in a heat wave, but then body temperature regulation is probably not an easy assignment.
Depending on what theory you believe, some people may not shiver because their ANS doesn’t have that reflex, or their bodies are better at temperature regulation than the rest of us, or they’re just lying about never having a pee shiver.