I'm in the middle of a 12-hour fast before getting my blood drawn again. The last time I had it done a few weeks ago, it was immediately after having been very ill (I had what many people call the "stomach flu," and I hadn't been able to keep anything down for 36+ hours).
The results of that test were overall quite good, but my blood sugar and creatinine (kidney) levels were elevated. Because of that my doctor decided she wanted to do a series of blood tests over the course of 3 months to make sure those levels weren't just elevated due to my illness.
So here I sit, chugging water to fill my empty belly before I go get "leeched!"