What is the medical definition of HTN?

HTN stands for hypertension, also known as high blood pressure. It is a common medical condition where the pressure of blood in your arteries is consistently too high. Blood pressure is measured in millimeters of mercury (mmHg) and is indicated by two numbers, the systolic pressure (the pressure when the heart beats) and the diastolic pressure (the pressure when the heart relaxes). Hypertension is defined as a systolic pressure of 140 mmHg or higher, or a diastolic pressure of 90 mmHg or higher.