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. From Healthy Resources 10 Rheumatoid Arthritis SymptomsHigh-Risk Myelofibrosis: Treatment Options10 Ways to Take Control of Your Migraine Featured Centers What Are the Best PsA Treatments for You?Understanding Biologics 10 Things People With Depression Wish You Knew
