Biomarker (medicine)

A biomarker is something doctors look at in a patient's body to find out information about a medical condition. Just like a thermometer measures a person's temperature, a biomarker measures something else in the body to help a doctor understand what might be happening. For example, there are biomarkers that tell doctors if a patient has cancer or a heart condition. Doctors measure these biomarkers using special blood or urine tests that can tell them if something is wrong.