Hi if my left arm get cramps when i sit for too long what is the symtom?

Arm cramping: Consider recent overuse from workout, etc. That can cause muscle soreness/pain. Consider cervical radiculopathy that is positional--pinched nerve symptoms.

Maybe a nerve issue: Pay attention to how your arm is positioned. If you leave a nerve in a stretched or pinched position blood flow will be cut off and the nerve won't work right. Try moving your arm to different positions more frequently.

Varies: Multiple potential options. Thoracic outlet syndrome would be one consideration. Don't hesitate to be seen for a thorough evaluation.