Over time, high blood pressure or hypertension (HTN) causes damage to the lining of blood vessels in 3 ways:

1. Blood vessels consist of several layers one of which is smooth muscle. These smooth muscles allow the blood vessel to stretch to meet the demands of variable blood volume and pressure. At higher pressures, the vessels lose their stretchability and the muscle thickens. The older we get, the less our vessels stretch. This leads to a narrowing of the blood vessel where clots can easily block off the blood vessel entirely leading to a heart attack or stroke.
2. High blood pressure over time damages the lining of the blood vessel setting the stage for clots to form on the lining of the vessel. This leads to a certain amount of “stickiness” as platelets clump together. If these clots rupture, they can lead to a heart attack or stroke depending on where they lodge.
3. Increased blood pressure can also cause the lining of the blood vessel to eventually weaken, causing tearing or bulging of the artery. This is known as an aneurysm. Because arteries are under a great deal of pressure anyway, this area can weaken and eventually rupture causing death.