Why I Feel Pain In Left Arm Why Does My Left Arm Feel Numb?

Why does my left arm feel numb? - why i feel pain in left arm

There are about an hour, my left arm started feeling a little numb. I also feel a slight pain, maybe two inches from the armpit. The anoying. It feels like a rope tied around his arm and cut off circulation. Furthermore, it hurts more when I move in certain positions. Why do I feel?