Hypertension – Long term effects of high blood pressure
The heart is a muscle that needs its own blood supply, which is brought to it by the coronary arteries. If these arteries are narrow, blood does not get to the heart muscle efficiently, the heart needs to work a bit harder than usual, E.g. when you are walking up a hill the heart muscle cannot get the blood supply and oxygen that it needs. This causes pain in the chest, known is myocardial is chaemia or angina. If a coronary artery narrows and then a blood clot forms, the part of the heart muscle that relies on that coronary artery dies.
This is known as coronary thrombosis, a myocardial infarction or a heart attack. Over the years, as arteries narrow and become less elastic as a result of hypertension, it gets harder and harder for the heart to pump blood out efficiently to the rest of the body. The increased work load eventually damages the heart and impairs it performance. Fluid collects in the lungs, causes shortness of breath. This is known as congestive cardiac failure.
Narrowing of an artery that carries blood and oxygen to the brain can lead to temporary loss of function in the part of the brain served by that artery, this is known as Transient Ischemic Attack (TIA) Permanent closing off of the artery with a blood clot results in the death of the part of the brain reliant on that artery, which results in a stroke. Smaller blood vessels in the legs can be damaged, resulting in the legs getting damaged, resulting in less blood getting to the feet, and pain in the calf muscles on walking.
When blood vessels supplying the kidneys are affected, the result may be gradual kidney damage. This is why a blood test to check kidney function is a vital part of regular check ups for anyone with hypertension.
The small blood vessels in the eyes can also be affected, although this may not become apparent until the damage is extensive. Rarely, in severe hypertension there may be damage to the retina with hemorrhages. This condition is called malignant hypertension, although with treatment the outlook is very good.