I was going numb in the legs, and my Chiropractor diagnosed tight tendons on the outside of my legs. I thought he was crazy, but did the stretches and had immediate relief. When I started karate, we started doing a lot of stretches and now I don't have the problem at all.
For a time, as I bulked, I had the problem in my arms, they would go numb everynight and if I held them in the wrong position during the day. I stopped sleeping on my side (now I sleep with my shoulder pushed forward, so I am resting on the shoulder blade) and I make sure to roll over every hour or so during the night, and that problem stopped, too.
IDK if your problem is similar, but these things worked for me and today I hardly ever experience numbness.