I've lost about 20 pounds in the last eighteen months. I don't know why. I have a cooperative doctor who will run tests if I suggest them but doesn't do a lot of suggesting herself. What's the next thing I should try?
I've run a number of tests already. Most notably, my thyroid and sugars both came back clean, more than once. My blood tests have been mostly clean (low iron, elevated ESR) and I don't have B12 deficiency. I had a chest x-ray that looked fine and a stool sample that turned up negative for whatever the standard battery of parasite tests were. I had a recent gyno exam that was also normal. I don't have any other symptoms and I'm 30.
What is the next test I should be running? What should I be doing to figure this out?