When I sleep the back of my head goes numb. Does this cause brain damage? Lack of blood flow?

Nerve Compression. Likely you are compressing your occipital nerve, particularly if lying on your back causes the symptom. The numbness in the back of your head may be on one side or both. Repositioning to take pressure off the nerves should lead to slow return of sensation. Compression of this nerve will not affect brain function. If you are unsure, or your symptoms seem different from this, consult your doctor.

Related Questions

I woke up with a sore neck and numb head from the position I was sleeping in. Did this position cause lack of blood flow? Brain damage?

No. You probably pinched your occipital nerve which does not affect blood flow. I would get a better pillow, only sleep one one pillow and if you have no stomach problems try some ibuprofen 600 MG very 6 hours for a few days. If you have had any sort of injury, whiplash or head injury in the past you should see a dr and be examined. Read more...