Is it a "go to sleep" type numb? That can happen to you if you hit your "funny bone" or if you're laying on the nerve that causes your arm to go to sleep. I think that's no big deal because that's natural and anyone can cause that to happen. If it's NOT that type of numbness, then you need to get it checked out FAST. That's one of the classic indicators of stroke.
Awaiting outcome of cervical MRI
...Please carry me through this...
ellekay, even though it won't hurt to check it out with a doctor, i wouldn't worry about it too much.
it used to happen to me all the time when i had a really bad panic attack, right in the middle of it, and it only scared me more. in fact, the left side of my body is always affected by panic attacks and anxiety. my left shoulder would go numb, my left hand would tingle and go numb...i would get these shooting pains throughout my left arm (very, very unpleasant feeling)...and believe me, there is nothing physically wrong with me.
now, i don't exactly know what your particular problem is, but just so you know, it is very, very possible for that kind of symptom to be cause by panic and anxiety.
Does it only happen when you sleep? If so, you are probably just laying on your arm funny, cutting off the circulation or something. If it happens when you have panic attacks, that is a normal symptom. When I have panic attacks, My whole body goes numb/tingly. Both arms, both legs, my chest and stomach, my head. IT is really scary but it passes. If your going numb from some other reason than those mentioned above, I would def. go see a doctor.
mY LEFT ARM WOULD ACHE AND I TOLD MY DOC AND HE SAID I MIGHT HAVE NERVE DAMAGE BECAUSE I ALWAYS SLEEP ON MY LEFT ARM AND IT GOES NUMB WHILE I AM ASLEEP AND I DO IT A LOT. I DON'T THINK THERE IS ANYTHING WRONG BUT IT WOULDN'T HURT TO GET IT LOOKED AT! SOMETIMES MY LEGS ACHE TOO! HOPE YOU FEEL BETTER!