QotW: Why do some people shiver when they pee?

Listener Eleanora asked: "I want to know why my dad shivers when he pees." Phil Sansom managed to find the answer from neurologist Kieren Allinson and Jalesh Panicker, a neuro-urologist...

Eleanora - Hi! I want to know why my dad shivers when he pees.

Phil - Eleanora told us she also experiences this herself, so her dad is not unique - and neurologist Kieren Allinson agrees.

Kieren - “Pee-shivers” - or having an involuntary shiver when you go for a pee - is a real thing that some people do experience.

Phil - Jalesh Panicker, neuro-urologist (a fantastic job title) says it’s more often experienced by boys and men...

Jalesh - ...particularly when peeing large volumes standing up. We don’t fully understand why it happens, however there are a couple of possibilities.

Phil - Jalesh and Kieren can take it from here.

Jalesh - The first idea is more from common sense, and based on the fact that we shiver when feeling cold. When peeing, warm private areas and pee are exposed to cold air...

Kieren - ...and you might just shiver automatically to warm up. But I find this harder to believe as it would cause shivering when you removed clothing generally, not just when you go to the toilet.

Jalesh - It’s more likely that pee shivers is down to nerves.

Kieren - It has to do with the autonomic nervous system, which is part of the nervous system which controls involuntary things like body temperature, sweating, shivering etc.

Jalesh - The decision to pee or not to pee may be voluntary; however, the act of peeing is controlled by the autonomic nervous system. The parasympathetic component (which handles resting state functions such as digestion) springs into action and instructs the bladder muscle to push urine out of the bladder. When urine leaves the body, oddly the blood pressure drops slightly and the sympathetic component (which handles the fight or flight response) then kicks in, releasing a shower of neurotransmitters in an effort to raise the blood pressure. This results in mixed signals between these two components of the autonomic nervous system, which is thought to trigger an involuntary shiver.

Kieren - It affects men more than women, probably because they stand up to pee, and therefore are more prone to the drop in blood pressure, because the blood has to get to their head past more gravity. Unfortunately we don’t know why it affects some people and not others.

Phil - So let me summarise. Your autonomic nervous system is the nerves you can’t control. It’s got multiple parts, one of which, called the parasympathetic component, helps you pee. This can lower your blood pressure, accidentally triggering the sympathetic component, which may be giving mixed signals which cause the shiver. Thanks to our forum users for coming to the same conclusion - plus, user Evan pointed out that sometimes a shake gets out the last few drips. Next time - a question that is music to my ears! It’s from listener Dennis.

Dennis - Assuming there are a finite number of musical notes - chords, notes, octaves - at what point, how many years, would we use all combinations of musical themes such that no more music could be created?