I don't so ANYTHING with needles <--- huge needle phobic. And hell I'm about to finish vet school in the next week or so.

Anyway, as for what they are checking...there's usually up to 6 viles, and the colors on the top determine what exactly they are looking for. Usually the most important ones are CBC - complete blood count, Cholesterol - HDL, LVL, glucose (if they test for it), T3, T4 and a few others. Labwork is also used for other tests such as pregnancy, not that this will concern you. There are other tests that require your consent, such as HIV. They will not run this if you don't ask for it.

What you eat the day before can throw off levels...especially cholesterol. Try not to eat anything with a lot of fat and sugar for a day or two prior. It doesn't always throw it off, but it can...so they are just covering their bases. And you should be able to drink water prior to the lab work...if you don't like needles drink plenty of it so you don't pass out. If your on any medications, definitely tell them...though I'm always knocked out with oral sedations prior to any labwork and they never get told and it comes back fine. All depends on what your taking.

Also, they run your blood type everytime. If they are charging you to find that out, they are ripping you off. It's part of the workup. They should tell you if you request it...plain and simple. I really have a problem with todays medical field...so few people actually care and are just in it for the long term money.