Blood pressure commonly rises as you get older, but this normal increase occurs more quickly in people who already have high blood pressure.

Untreated high blood pressure can damage the delicate lining of the blood vessels. After a blood vessel is damaged, fat and calcium can easily build up along the artery wall, forming a plaque. The blood vessel becomes narrowed and stiff (atherosclerosis), and blood flow through the blood vessel is reduced. Over time, decreased blood flow to certain organs in the body can cause damage, leading to:

• Coronary artery disease, heart attack, and abnormal heartbeat.
• Stroke.
• Kidney (renal) failure.
• Peripheral arterial disease.
• Eye damage (retinopathy).

People with borderline, or "high-normal," blood pressure (120-139/80-89)-which is now considered "prehypertensive"-have a higher risk for developing high blood pressure and heart disease than those with blood pressure less than 120/80 millimeters of mercury (mm Hg).⁴

In addition, men who have high systolic blood pressure during middle age (50s to 60s) may show a greater decline in mental ability later in life (after age 75) than men who do not have high blood pressure earlier. Short-term memory and attention span are most affected.

Elevated blood pressure readings may not always mean you have high blood pressure. For some people, just being in a medical setting causes their blood pressure to rise. This is called white-coat hypertension.

Malignant hypertension (hypertensive crisis) is high blood pressure that increases rapidly. The cause may be unknown, or it may be caused by a medicine or another condition.

Isolated systolic high blood pressure is when systolic blood pressure is elevated above 140 mm Hg, but diastolic blood pressure stays at less than 90 mm Hg. This type of high blood pressure is more common in older adults, especially older women. If you are older than 50, a systolic blood pressure over 140 is a more important risk factor for heart disease and stroke than your diastolic blood pressure.¹