What does precursor mean in medical terms?

A precursor is a substance that is transformed into another substance, especially one that is essential or significant in a reaction or process.

In the context of medicine, a precursor refers to a substance that the body can convert into another substance, which may have pharmacological activity or play a role in a disease process. In the context of medical laboratory diagnostics, a precursor can refer to a substance that is converted into another substance during a laboratory test or assay.