Hypertension in an individual can cause them to be at an increased risk of having a heart attack. Blood pressure describes the amount of force the blood has on the vessel walls as it flows through them. Healthy blood vessels can expand and accommodate this to a certain extent. However, the blood vessels can become damaged when the individual has high blood pressure consistently over some time. The blood vessel linings and walls become damaged, allowing for easier penetration by fats and other substances known to form plaque in the arteries. A heart attack can happen when plaque builds up and obstructs the coronary arteries. Another mechanism through which hypertension can cause a heart attack involves the strain high blood pressure puts on the muscle tissues of the heart itself. The muscular walls of the heart can grow larger and become thickened. An enlarged heart can cause a heart attack because it compresses the coronary arteries, cutting off blood flow to the heart tissues.