I have constant pain in my right arm and pins and needles what is it ?

Neuropathy: By description, it sounds like you have a pinching nerve in either your neck (cervical) area or your shoulder, where nerves can commonly get "pinched" and cause "parasthesias." You need to see a Doctor and get an evaluation, with some testing most likely such as an EMG, which would determine the extent of your issues. Then any treatment would follow. Best wishes to you.

Arm pain: it depends on where it is on your arm and where the tingling is located. If it is in the lower arm it may be carpel tunnel syndrome where the median nerve is entrapped at the wrist causing pain in the thumb and first three fingers. Or it could be cubital tunnel syndrome where the ulnar nerve is trapped at the inside of the elbow causing pain inside arm and other fingers. See you doctor for help