Hi Dr. Grief, my dr left a message that my T4 was very low last Friday. My oncologist had tested TSH about a month ago and it was low. Does that mean that something is wrong with my pituitary gland? My chemo for breast cancer ended last November. I am on the 5 year med now. I also have fibromyalgia and narcolepsy. I have been feeling really bad and asked to cut my work hours for a while until I get things under better control. I did get very strong chemo and it took 6 months for me to get back to work. I thought a little hx might help. What are your thoughts please? Thanks, donna