As odd as this will sound, you can do blood tests online. By that, I mean, you pay a fee online, they make an appointment for you (at your convenience) to come into a lab center near you. They draw the blood. 48 hours later, you get your results via email (or regular mail, if your prefer).
You can pick and choose what type of blood tests you want, what you want them to look for, etc. The blood tests come with an explanation.
I've used healthcheckUSA in the past with excellent results. I've also used directlabs and labtestsonline.
We're also UPing ... so it's what I've done to check. Depending on the type of test, as well as where I went, the fees ranged from 50 to 75 to 150.