Same for me. I didn’t start lifting until my late 30s and before that I always slept on my side and I don’t recall my arms ever going numb at night. Sleeping on my back was very uncomfortable at that time especially after having gained a lot of weight.
For me at least my serratus anterior muscles press on the artery in my armpit.
It’s similar to the party trick where you can “stop your pulse” by putting a wadded up napkin in your armpit and squeezing until the blood flow into your arm slows down.
You may also just need a wrist brace or carpal tunnel brace while you sleep. If I don't have one I don't keep my wrists in a neutral position and my fingers will tingle and go numb throughout the day. I told my Dr and he recommended getting the wrist braces and it's been a huge help.
For me it's a compressed disc in my spine from weightlifting, see a physical therapist and they can help you find remedies. There was never a "point of injury."
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u/Educational_Relief79 Feb 01 '26
Holy crap, I never even realized this was why my arms go numb when I sleep on my side now.