A thyroid-stimulating immunoglobulin (TSI) test is a blood test that can help diagnose Graves’ disease, an autoimmune condition that causes an overactive thyroid. A TSI test measures levels of TSIs in ...

Diurnal cortisol tests measure your cortisol levels at various points, from the time you wake up until the time you go to bed. They can help a healthcare professional visualize your adrenal gland ...

This article was reviewed by Felix Gussone, MD. If you’ve been feeling a bit more couch potato than go-getter lately, dragging through the day, snapping at people for no reason, or wondering where ...