Blood pressure is one of the most important indicators of cardiovascular health. It measures the force of blood pushing against your artery walls as your heart beats and rests. A reading contains two numbers: systolic pressure, the top number, measures pressure when the heart contracts, while diastolic pressure, the bottom number, measures pressure while the heart relaxes between beats.

Although blood pressure often rises with age as arteries become stiffer, getting older does not automatically make high blood pressure normal or inevitable. For adults, readings below 120/80 mmHg are generally considered normal under widely used U.S. guidelines. Readings of 120–129 with a diastolic below 80 are considered elevated, while persistent readings beginning at 130 systolic or 80 diastolic may fall into the hypertension range. But there’s an important reason you shouldn’t simply accept higher numbers because you’re getting older.