Hi Elaine:
It all depends on what type of results your doctor wants from these blood tests. If your physician wants to find out how your liver is responding to the estrogen, or at what level your testosterone is after HRT, you normally don't need to fast. However, if your doctor wants to know your cholesterol levels, which also change with HRT, then you do need to fast.
If you don't understand your lab results, you can always request a written explanation of such results, or if you prefer you can call the hospital where you had your lab work performed and ask the nurse on call to explain the results you obtained.
tinkerbell