Great question! I always advocate getting a physical, complete workup of blood, before taking charge of one's health. It's a great way to get confirmation and to detect issues accurately.
Just get a basic physical. Tell the doctor it's something you do every year, and get copies of the results (because gee, I change jobs often and that means changing benefits, HMO's and doctor's, and I like to have my own personal record etc.). :)
Some life insurance companies require a basic physical, so you can say you're getting whole life an dthey require it. :)
You do NOT have to wait for your doctor to tell you what to do; you can easily ask because we're supposed to ask! We're supposed to monitor things like our cholesterol! You can tell him you have a family history of certain things like hyperthyroid so gee, shouldn't you get that tested? Yep, thyroid panel on the way. :)
the basic physical includes basic metabolic functions and a urine test. This lets you know how your major organs are doing, red blood cell count, etc. My doctor has a great lab, for one price I get both TSH (thyroid) and basic metabolic and CBC. :)