"Go and see a GP" or "consult an osteopath"
Seriously?
Forget that and find a local
sports injury specialist-
http://www.csp.org.uk/
Don't waste time with the NHS to get this diagnosed.
GP's are clueless clowns when it comes to musculoskeletal problems and will normally immediately (or in some cases depending on just how stupid they are,
eventually) pass you on to an NHS physio department somewhere.
Sadly, this is
also a waste of time because they simply are not allowed to take the required time to properly assess your injury, nor do they have any idea or interest in who you are, you are simply another "client" or number on their list for the day.
Once you're diagnosed,
if the private physio suggests seeing a consultant or perhaps other specialist investigations like scans etc, get a letter from the physio to your GP to that effect. The GP will almost certainly follow whatever the physio advises, if they don't, then demand to see someone else and make it clear that
you are not satisfied.
The
chances are that your walking geometry has altered due to your injury, it happened to me, both times I had broken ankles and it wasn't till I was fortunate enough to come across a local private physio, who could take the time to properly assess me and the aftermath of my injuries, (as well as offer well thought out advice and treatment plans) that I finally got somewhere near to being sorted out. I ended up with a series of strength building exercises and a pair of orthotic insoles, which helped me no end.
Okay so you'll be paying around £45 for a consultation but you'll get straight forward advice on whats wrong and how best to sort it out. Much better than being messed around by overpaid GP's and indifferent NHS physio departments.
If you can't afford to get a private diagnosis, the chances are that you'll end up just having to live with the pain, till you either stop doing whatever it is that causes the discomfort or you ignore it and keep going till it goes away due to you re-training your legs, or dose yourself with gut rotting anti-inflamatories
Of course, you'll end up walking funny and developing knee, hip and back issues over time, as well as ending up with knackered guts but the NHS is there to fob you off with third rate treatment for
those issues too, as and when they manifest themselves ( as opposed to doing a proper job in the first place and avoiding the issues developing in future?)
good luck but
even if you're hard up, invest some money in finding out exactly whats wrong as quickly as possible, then take whichever route suits you after that.
Best wishes
Steve