you know when you sleep and you are on your side and cut off circulation to your arm and you wake up and your arm has no feeling til your blood flow comes back. I wake with that feeling but I m sleeping on my back. That s the closest thing i can compare it to. It has never happened til the last few weeks, several times,left arm. I m a 50 yr old male,good shape. Exercise regularly , adopted, don t know family history.