I just read an article that had a test to see if you have tennis elbow or not. Having the great fortune of never having this problem (knock on wood), I always wondered if my elbow hurts at all is it Tennis Elbow?
Without further adieu, Here is the test:
Diagnosis is really very simple. Hold your arm straight out, make a fist with your palm down, and try to tilt your hand up while holding it down with the other one. Pain on the outside of the elbow? That’s it. We may want to X-ray it to be sure nothing’s fractured, but chances are it’s just a miserable lateral epicondyle.
Reference: http://www.nydailynews.com/sports/more-sports/running-doc-handle-tennis-elbow-article-1.1887341
A good technical breakdown of what Tennis Elbow (Lateral Epicondylitis) is can be found here: http://orthoinfo.aaos.org/topic.cfm?topic=a00068