Why Your Limbs Feel Like Static When They Fall Asleep

For something that's supposed to be restorative, sleep can be a truly stressful experience. Aside from worrying about how much sleep we actually need, there are so many considerations that come with getting a restful night. For instance, did you know that too much sleep may actually reduce your lifespan? That there's nightmares, which aside from being upsetting and terrifying experiences in and of themselves, may even predict a real-life illness? This is to say nothing of the even more upsetting night terrors or truly terrifying experiences such as sleep paralysis.

Far less terrifying, but disconcerting nonetheless, is the experience of waking up in the middle of the night with a limb that apparently went limp at some point while you were unconscious. We've all woken up with a tingling in our hands or limbs at some point, and the feeling can be mild or surprisingly intense. It does, of course, eventually subside, but we've all surely been convinced in our somnolent state that our legs or arms will remain forever dead.

It's at least reassuring to know, then, that this sort of experience is actually very common, typically harmless, and has nothing to do with some terrible underlying condition. Still, the question remains of what exactly is going on in these moments when we wake up with completely dead limbs.

There's actually a name for the experience of waking up with limbs that have apparently gone to sleep: Transient paresthesia. This common condition has everything to do with body positioning and typically isn't anything to worry about. The feeling reliably returns to your limbs within a few seconds or so, bringing with it a tingling, pins and needles sensation. But what exactly is going on with transient paresthesia?

The term paresthesia refers to a tingling or numb feeling which is produced when a nerve becomes irritated and starts sending specific signals to the brain to alert it that something is off. Usually, electrical impulses move down the nerves of your spine and out to your limbs without impediment, before moving back up the spinal cord to your brain. However, if something stops the impulses from moving, like pressure on the nerves, it not only results in a loss of feeling, or numbness, but can produce the tingling feeling, or paresthesia.

In the case of transient paresthesia, this feeling is, as the name suggests, transient. While sleeping, it's common for us to lay on our limbs, putting pressure on the nerves and producing numbness, or "obdormition" to use the technical term. When we wake up, and relieve the pressure on our nerves, the nervous system often becomes hyperactive as it starts firing up again, which is where the static-like feeling of pins and needles comes from.In order to stop the feeling of static, or pins and needles, simply rearranging our sleeping position is all that's needed.