Well you can see a doctor and have them check your heart to see if your heart is doing well, if that is ok then you might have what they call tennis elbow. You don't have to play tennis to get it either, you just might have bumped your elbow or had strained it too much. If they find problems in your heart, they can catch things early and correct the problem.
Yes, a pinched nerve or tendonitis?
Sounds like a pinched or irritated nerve.
No doctor's visit?