# Can you injure a limb if you sleep on it and cut off blood supply? **URL:** \ **Category:** Factual Questions\ **Created:** [September 16, 2011, 6:07am UTC](https://boards.straightdope.com/t/can-you-injure-a-limb-if-you-sleep-on-it-and-cut-off-blood-supply/596489 "2011-09-16T06:07:12Z")\ **Posts on this page:** 7\ **Page:** 2
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [September 17, 2011, 12:29am UTC](https://boards.straightdope.com/t/can-you-injure-a-limb-if-you-sleep-on-it-and-cut-off-blood-supply/596489/21 "2011-09-17T00:29:11Z")
> [@AaronX](#): > > About the rubber band castration, I’d heard of that too. I always wondered how do they get the band over the balls? If they were that tight, wouldn’t it be impossible to stretch them that much? You use a tool called an [elastrator](http://www.omafra.gov.on.ca/english/livestock/beef/facts/07-029f1.gif). ---
**Author:** ![Euryphaessa](https://avatars.discourse-cdn.com/v4/letter/e/c5a1d2/32.png) [@Euryphaessa](https://boards.straightdope.com/u/Euryphaessa)\ **Post date:** [September 17, 2011, 2:14am UTC](https://boards.straightdope.com/t/can-you-injure-a-limb-if-you-sleep-on-it-and-cut-off-blood-supply/596489/22 "2011-09-17T02:14:23Z")
> [@dracoi](#): > > Rubber bands really do stretch just fine. > > I don’t know about castration, but I did have something like that happen with a cat’s leg. Somebody wrapped rubber bands around our cat’s leg, tightly enough to constrict the blood flow. The cat didn’t come back to us for a couple of days. By the time it did, damage had already been done. The vet had to cut off the paw and all of the skin sloughed off up to the point where the rubber bands had been. It took years to heal to the point where we didn’t need to keep a bandage over the lower leg. Sorry for the hijack, but this made me incredibly sad. Poor kitty. ---
**Author:** ![horsetech](https://avatars.discourse-cdn.com/v4/letter/h/dec6dc/32.png) [@horsetech](https://boards.straightdope.com/u/horsetech)\ **Post date:** [September 17, 2011, 6:14am UTC](https://boards.straightdope.com/t/can-you-injure-a-limb-if-you-sleep-on-it-and-cut-off-blood-supply/596489/23 "2011-09-17T06:14:58Z")
Dracoi, poor kitty indeed, and sadly not uncommon. ☹ To follow up on brossa’s post, lying in one position for a long time on a hard surface can cause widespread rhabdomyolysis (skeletal muscle breakdown). This doesn’t just cause muscle damage and cramping: the lysed cells release their contents, including potassium (which is normally present at much higher concentrations within cells than outside cells) and myoglobin. If it gets severe enough, the elevated potassium level can cause heart arrhythmias. Also, myoglobin can damage the kidneys if there is enough floating around, and the dehydration often present in these scenarios exacerbates the problems of impaired renal function and electrolyte abnormalities. This can happen if, say, an elderly person falls, breaks a hip, and lies on the floor, unable to move themselves to a phone, until they are found. ---
**Author:** ![KarlGauss](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/karlgauss/32/3713_2.png) [@KarlGauss](https://boards.straightdope.com/u/KarlGauss)\ **Post date:** [September 17, 2011, 9:07am UTC](https://boards.straightdope.com/t/can-you-injure-a-limb-if-you-sleep-on-it-and-cut-off-blood-supply/596489/24 "2011-09-17T09:07:39Z")
> [@kanicbird](#): > > OK, if it’s just pressure on the nerve, as opposed to circulation being cut off, what is the mechanism that limbs are lost? Don’t be so fast to abandon that mechanism . . . That being said, although it’s theoretically possible to lose a limb by cutting off its blood supply (say, by passing out drunk in a position where the blood flow to the limb is compromised), it’s much likely that one loses a (large) patch of skin. As an example, imagine that someone has a stroke, becomes paralyzed, and thus cannot move. Let’s say they’re on their back. Those points of the body (skin) in contact with the floor (often in the form of ‘bony prominences’) are being subjected to continuous and uninterrupted pressure. Very often, that pressure is higher than the blood pressure. That means that blood won’t be able to flow into the ‘squashed’ tissues. If it persists long enough, the squashed tissue (e.g. skin) will die (so-called pressure necrosis). ---
**Author:** ![jnglmassiv](https://avatars.discourse-cdn.com/v4/letter/j/f07891/32.png) [@jnglmassiv](https://boards.straightdope.com/u/jnglmassiv)\ **Post date:** [September 18, 2011, 8:05am UTC](https://boards.straightdope.com/t/can-you-injure-a-limb-if-you-sleep-on-it-and-cut-off-blood-supply/596489/25 "2011-09-18T08:05:48Z")
> [@Blake](#): > > You use a tool called an [elastrator](http://www.omafra.gov.on.ca/english/livestock/beef/facts/07-029f1.gif). Get that thing away from me. ---
**Author:** ![BigT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bigt/32/12044_2.png) [@BigT](https://boards.straightdope.com/u/BigT)\ **Post date:** [September 18, 2011, 8:39am UTC](https://boards.straightdope.com/t/can-you-injure-a-limb-if-you-sleep-on-it-and-cut-off-blood-supply/596489/26 "2011-09-18T08:39:05Z")
> [@jnglmassiv](#): > > Get that thing away from me. At least one guy on Dirty Jobs argued that this was more inhumane than just cutting it off, judging by recovery time of the sheep they used it on. ---
**Author:** ![Wesley\_Clark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wesley_clark/32/20581_2.png) [@Wesley\_Clark](https://boards.straightdope.com/u/Wesley_Clark)\ **Post date:** [September 18, 2011, 1:53pm UTC](https://boards.straightdope.com/t/can-you-injure-a-limb-if-you-sleep-on-it-and-cut-off-blood-supply/596489/27 "2011-09-18T13:53:58Z")
The lead singer of megadeth, after years of risky behavior and drug abuse, once fell asleep with his arm hanging over the back of a hard bench (which put a lot of pressure on I believe his radial nerve). After waking up and it taking a long time to get use of his hand again he was told he’d never play guitar again. However after a year or so of rehab he was back. So that was ironic that the drugs didn’t hurt him but sleeping on a bench did. Personally I get this all the time and it worries me. But carpal tunnel syndrome involves compression too and as far as I know people don’t get amputations or lose a limb due to that. [Previous page](https://boards.straightdope.com/t/can-you-injure-a-limb-if-you-sleep-on-it-and-cut-off-blood-supply/596489.md?page=1)