Educational Content: This article is for informational purposes only and does not constitute medical advice. Always consult a healthcare provider for diagnosis and treatment.
Definition of Hg
Medically reviewed by Min Clinic Staff | Updated: January 2026
Hg: Symbol for the metallic element mercury.
The abbreviation "mm Hg" means millimeters of mercury, the height of a column of mercury, as in a blood pressure reading.
Mercury is poisonous to people. See Mercury poisoning.