I just posted this in another thread, but you have the same issue that myself and many others have. You may want to see the other thread regarding this issue [it's the very last link on this page] as there is some additional insight to this problem there. Here is what i've posted elsewhere:

i first awoke to this feeling on christmas day 2005, while laying on my back with my arms to my sides - a very natural & non-contorted position. This alarmed me, as one immediately thinks the worst [heart attack]. After standing, it went away. I'm a 39 y/o male who is in the prime of his sudden heart-attack years, and i'm about 20 lbs over my ideal weight.

Three months later, i'm still plagued by this problem, mostly at night and mostly in my left arm but occasionally in both. From my research, it looks to be a common "pressure palsy" from a nerve either being pinched or the blood flow being reduced or stopped to the affected limb. Typically i'm a side sleeper, and surprisingly this occurs most when on my back.

Approximately two years ago, I was rear-ended at an adjusted speed of about 40 mph. Since then, beginning about two months afterwards, i've had neck & shoulder pain, sciatica [numbness in my right leg (removing or relocating my wallet to my left-rear pocket usually resolves or avoids this)] and finally this arm numbness. Unfortunately for me, the statute of limitations has run out so I cannot pursue his insurance company to pay for any related procedures, and I fear that I will continue to have ongoing and increasing health issues because of that accident.

Seeing the chiropractor usually brings lasting relief from this annoyance.

Perhaps these links will be of help to you. I suggest that you see a doctor in any case, but especially soon if you're additionally experiencing chest and/or throat pain as this may be an indicator of heart disease or the onset of a heart attack. Good luck & take care of yourself :)

http://www.Tvo.Org/yourhealth/medicine101/ nightnumb.Html

http://This link has been removed/forums/neuro/archive/8811.Html

http://This link has been removed/forums/neuro/messages/33394.Html

another thread discussing this topic on eheathforum:
http://ehealthforum.Com/health/topic1326.H tml

Sleep study may find out why you seem to be going hypoxic.
Drop in blood flow shalow breathing all this can cause sleepy arms.

And this isn't the only page of this on this same sight. Now if anyone went to a Dr.. and got us an answer I went to my Dr.. the other day and she sent me to an orthopedist in which I didnt make the appt. yet but she said arthritis but I dont think so.... LOL not that I am a Dr. or anything. I know I kind of sleep on my arms but I am 32 and have always done that. This has been happening since Novemeber '06. Waking up a few times a night never really sleeping. I have bags under my eyes from not enough sleep!!!!! I am going to try stretching every night before I go to sleep someone suggested that also. It cant hurt!!!!! Good luck! If i get any answers I will let you know it may help everyone else!

Hi,
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It sounds like you have cervical radiculopathy from possibly a bit of nerve root impingement in your neck. An orthopedist or neurosurgeon can diagnose this for you with an MRI of your neck. There are many treatment options:

Medication
Oral steroids
Injected steroids
Manipulation (chiropractic or Oseopathic)
Physical therapy
surgery

Need to know what is going on and why this is happening to me I haven't been able to get a good nights sleep in so long I am constantly tired from not having a good nights sleep. I wake up throughout the night from all the horrible numbness in my whole arms both of them and now it is affecting me during the day. Help what is this!

Hi Jessie8 - it's March 12 '09 - It sounds like I have VERY similar symptoms as you...please tell me if you are better, and if you found out what is causing this!!! It hurts so bad & i get little sleep as well.

I recently got CPAP, pressure of 14 following sleep study with 506 episodes of apnea and hypopnea, and O2 falling to 60%. I have been on the machine for less than one week. Last night and two nights agp I awoke with tingling, numbness and pain in my left arm. It took a few minute the first night and about 45 min last night to go away. No other pain any where else. I usually sleep on my right side, but awake on my back. CPAP was in place. Help

I suddenly started getting pins & needles and a burning feeling in both hands and arms through the night. I read up about methods that would ease the discomfort.
I started a DVD work out and running on the treadmill every other morning...That worked.
Having mixed hot and cold showers.....that helped.
Keeping healthy and watching my weight....
But now I'm 33 weeks pregnant I can't execise...so I'm stuck for ideas of how to ease the numbness in both hands....Help!

Like Schoolnurselh, I started CPAP at a pressure of 9 about ten days ago, and since then, sleeping on my back, I have woken on several nights to find my left hand feeling 'fat' and numb. I plan on asking the Respirologist when I have a video conference with him in a week or so. Is there a link between CPAP and hand numbness or between sleeping on back and the numbness?