One of the most important skills for a doctor is knowing when a patient is truly sick or not. Also known as the eyeball sign or “hair on the back of the neck” sign, it’s the ability to determine within seconds whether a patient needs immediate attention or not.
Rural Doc writes about a case where this skill came in handy:
As I walked into her room, I felt a hair on the back of my neck rising up. Not literally, of course. The hair–and it is only one–has become the symbol for the feeling I get when a patient is really sick. It sprouted during the second year of my residency and has been with me ever since.
