What Causes Twisting Of Hand Inward With Stiffness In Fingers?

I m a 42 year old female. I have been experiencing (every other day and within that day 2-3 times a tingling feeling thru my left arm. I have also experienced (like 10 minutes ago) a Charlie horse pain like in my left inner middle arm where my hand actually goes inward and my fingers actually become stiff and it lasts around a good 5 minutes.