For a couple years now i have had extreme itches on my chest, arms, calfs, and back just after i break a sweat, please help me. thanks?

"heat rash?": When you get this rash, get an appt so the dr can see it, and then the diagnosis would be made and the best treatment could start. If only when sweating, possibly it is a type of minor heat rash that itches. Stress can also cause itching, called stress urticaria, and meds such as Hydroxyzine hcl, which are fda approved for both anxiety and itching can help. Good luck.