When a part of your body "falls asleep", can it cause any lasting damage?

I haven't seen anyone mention Decubitus ulcers/ bed sores.

While you are reading this, you are probably wiggling in your bed or chair, ever so slightly. These are micro movements. Micro movements help blood keep flowing through/around muscle and skin tissues.

Now lets say that you are redditing in bed, like many of us do. You prop yourself up on 3 pillows so that you are somewhat reclined, but mostly sitting up. You are really comfy and /r/aww is very entertaining so you hardly move at all. You sit on your butt in the exact same spor for a long time (30 minutes to an hour or so), eventually your butt kind of goes to sleep. Maybe even your heel goes to sleep, which you think is pretty strange, but you move your butt some, roll over on your side, and keep browsing /r/aww like nothing happened.

But something happened alright. The pressure of your body pushing your heel and butt into the bed made it hard for blood to flow in and out of those tissues, you made so very few movements, even micro movements, that they went to sleep. But when you noticed it felt funny, you rolled over.

Rolling over is very hard for bed-bound elderly and sick individuals. Hell, small movements like micro movements are hard too. Imagine laying on your back in bed All Day, All Night. Your butt would go to sleep at hour 1 and you wouldn't be able to move to make it wake up.

Now, tissue needs blood. What happens when tissue doesn't get blood, you get necrotic (dead) tissue. So that heel that doesn't get blood goes south, and fast. You can wind up with a horrible hole in your butt, back, or leg. Hell, anywhere really. Nursing homes and hospitals that are grossly understaffed and under trained may forget or just may not realize that immobile people need to be physically moved around, and propped up in various ways to keep bed sores from happening. Bed-bound people need to have their position very often, some places use pillows to help alternate pressure areas. There is a huge market for specialty hospital beds with air chambers that alternate filling so that pressure gets moved around without having to move the person as much.

Tl;dr: butt goes to sleep for 6 hours, eventually turns into a necrotic hole given enough time and neglect.

sauce- http://www.nlm.nih.gov/medlineplus/ency/article/007071.htm - http://www.parentgiving.com/shop/pressure-relief-mattresses-pads-88/c/

/r/askscience Thread