Here is my 2 cents. Get it diagnosed by a specialist like a physiatrist or orthopedic doctor. Assuming surgery is not required and surgery should always be the very, very last option. Get as long a referral as you can to a good sports physical therapist, one trained in bicycle problems if possible.
While you are doing the above get your bicycle professionally fitted at a bike shop with a certified fitter, paying particular attention to the points of body/bike contact.
The following is a diagnostic list taken out of one of my wifes physical therapy manuals specific to bicycle fit, function and pathology.
Hip:
Anterior -- Saddle too low/high saddle fore/aft bottom bracket width (triples/tandems) crank length - saddle-to-bar deferential saddle shape force production [how you pedal]
Specific conditions: Hip capsule restriction muscle imbalance or weakness
Posterior -- Saddle too low saddle fore/aft crank length saddle-to-bar differential saddle shape.
Specific conditions: Hip capsule, piriformis tight SI Joint, referral patterns ie: groin pain
I had some hip, knee and foot issues last summer (not anything serious like bursitis) and she had me do a few stretches and adjust my saddle and cleats and things got better.
Remember Floyd Landis, legally or illegally, road and won the Tour de France needing a complete hip replacement so there is hope!
Western Flyer
My hip hurts when I move my chin, . . .
and my heart is--what?
What's that? What's that you say?
You say today is. . .Saturday?
G'bye, I'm going out to play!
Shel Silverstein