When I sleep at night, it is not uncommon for my lower leg(s) to fall asleep or my arm or hand. When I wake up and change positions, the numbness leaves and sensation returns. My upper back is tight. I have a toddler and am still nursing him. He sleeps next to me, which requires me to sleep in somewhat uncomfortable positions without much space. Could the numbness I am experiencing be a result of the positions in which I am sleeping or something else? I had an MRI almost two years ago for migraines, and it was completely normal. But I have never had one for my spine.