What kind of doctor do I see for thinning hair?

My hair is thinning out and I want to go see a doctor about it. Not one of those Bosley guys or anything, just a regular physician who can check my blood and do all of that other stuff. What's the title of a doctor that would do all this kind of stuff and possibly recommend me for some treatments? I just want to know so I can call Kaiser and not be completely oblivious of the whole process.