During a nuclear stress test, you’ll be injected with a radioactive dye called a tracer. Some of this tracer will remain in your system for a time after the test. A nuclear stress test is a type of ...

Fentanyl is a synthetic opioid that’s 50-100 times stronger than the pain reliever morphine. While some people use fentanyl on purpose, many others get it in their systems without their knowledge.

These days, you can order up a test to find out your biological age, an estimate of how quickly or slowly you're aging compared to your peers. It's based on an analysis of modifications in your DNA. I ...