marker
Meaning of marker: Markers are measurable substances or traits that clinicians track to gauge whether a disease is present, progressing, or responding to treatment.
Definition of marker
A marker is a measurable biological substance, characteristic, or finding that provides information relevant to the presence, risk, activity, or course of a disease. Markers can include substances detected in blood or other body fluids, genetic changes, or specific features identified on imaging or under a microscope.
Markers serve different purposes depending on the clinical context. Some markers help identify whether a disease is present, others track how active or advanced a known condition is, and others help predict whether a person is more likely to develop a particular disease or to respond to a specific treatment. A single marker often needs to be interpreted alongside other clinical information rather than used alone.
Because a marker level or finding can be influenced by conditions other than the one being evaluated, its significance is typically assessed in context rather than in isolation.
Also known as
Used in a sentence
The laboratory panel included a tumor marker used to help monitor the response to treatment.
Good to know
A marker being elevated or present does not by itself confirm a diagnosis, since many markers can also be affected by conditions unrelated to the disease under evaluation.