This is back with a vengeance. I'm fairly confident it's related to weight lifting, specifically the press and bench press because they put so much compression on my palm. It mostly occurs when I go to bed and first wake up, but it's also been bothering me when I'm awake. It's in both arms, but it's significantly worse in my left arm. Grasping things with my hands causes a catching and zinging pain in my palms, sometimes my fingers go numb (usually the pinky and ring, but a couple times the middle and index), my elbow feels a varying intensity of a strike to the "funny bone", my armpit feel an uncomfortable pressing feeling, and reaching for things causes a tugging feeling from my armpit to my hand (as though the nerve were a rope being pulled taut). Last night, an intense pressure/throbbing pain on a dime sized area of my right palm started out of nowhere and lasted a minute or two.
I see my doctor about it tomorrow (I never did last time because it went away, coinciding with when I stopped lifting because of my shoulder problem). I'm not sure what he'll do about it besides tell me to stop all activity. I've been making significant progress in weightlifting the past few months after several years of a plateau, so I hope that's not the cause; even though, it most likely is. The only other potential causes I can think of are using wrist wraps when I lift, gaining body weight, and excess sodium's causing edema that presses on the nerves.