My super secret tip: for every little ache and pain - get a doc to give you an Rx to a physical therapist. It might turn out to be nothing, might turn into something worse - either way PTs are awesome magic workers. I will elaborate:
Drs are mostly limited to two things, surgery or an Rx (ok maybe a few other things).
PTs can't do those, but they can use stretching, massage, electro stimulation, exercise, and all sorts of practical, cheap methods to make you feel better.
(In the US at least) medical plan PT allocations are designed for the elderly when they break a hip. So there are usually a ton of free (or very subsidized) sessions in your plan. Way more than you'd need in a year, even if you do break something at 40.
They know the mechanics of the human body in a practical way that no doc has ever learned at school. I call it PT magic. Hey, your shoulder hurts, do this leg hammy stretch, voila and your shoulder feels better.
I can also share some of my other personal training goals (don't be fat, don't die early) and it's like having a subsidized personal trainer. And one better than any you could get at the gym.