The proper unit when recording a patient's blood pressure is mmHg, or millimeter of mercury. This is derived from a historical measurement of how many millimeters of mercury in a mercury manometer were able to be elevated by a particular pressure. Due to it's toxicity, are longer used in medical equipment, though the unit remains in use.

The left ventricle is the most commonly enlarged heart structure seen in chronic hypertension. The left ventricle must overcome the afterload of the arterial system by becoming hypertrophied. As a result, the heart gets remodeled to overcome the systemic high blood pressures. The left ventricle directly pumps blood from the heart to the systemic circuit.