Pee shivers
Also called: Post-micturition convulsion syndrome · Piss shivers
A brief involuntary shudder during or just after urinating. Many people seem to get it, men more often than women. It is widely known and almost completely unstudied.
How common
Does this happen to you?
How it works
Emptying the bladder is run by the autonomic nervous system, the part of the nervous system that works without conscious thought. It has two sides2. The parasympathetic side relaxes and empties. The sympathetic side holds, tightens, and also helps control blood pressure2. Urinating needs a switch from sympathetic to parasympathetic control and then back again.
The leading idea is that signals cross during that switch. A burst of sympathetic activity, meant to restore blood pressure as the bladder empties, sets off the shiver reflex by mistake1. A second idea is that the drop in blood pressure itself triggers the shudder. A third is that losing a volume of warm urine drops the body’s core temperature a little4. None of these have been tested.
Men seem to get it more often than women1. No peer-reviewed study of how common it is exists1. Standing to urinate may make it more common, which would explain part of the difference between men and women, but this has not been tested either.
How common it is
It seems common, but nobody has counted it. The medical-sounding name comes from a 1994 newspaper column, not from medical research14. It was adopted online and doctors have not replaced it. This is one of the most widely shared body experiences with the least research behind it.
Is it a problem?
No. The shiver is a brief muscle contraction like an ordinary shiver3. It is not known to be a sign of a bladder, nerve, or blood pressure problem. It is not linked to any disease and needs no treatment.
Mention it to a doctor only if it comes with:
- pain,
- fainting,
- a burning feeling while urinating,
- a sudden change in the urge to urinate itself.
Those point to something separate from the shiver.
Sources and further material
- Wikipedia Post-micturition convulsion syndrome
- Wikipedia Shivering
- straightdope.com What causes "piss shiver"? The column where the name was proposed. Lists the heat-loss idea and doubts it.
Missing something your body does? Tell me about it.
Related oddities
Random shivers
A single brief shudder that runs down the spine or through the whole body when you are not cold. Many people report them. Nobody has counted them.
Cold diuresis
Being cold makes you need to urinate. The body pulls blood away from the skin into the core, the heart reads this as too much blood, and the kidneys are told to dump water.
Seeing stars when standing up
You stand up fast, your vision goes grey or sparkly, and your head feels light for a few seconds. Blood has briefly pooled in your legs. It passes on its own.