Why is hypertension called the silent killer?

High blood pressure is often called the silent killer because hypertension makes your heart work much harder than it should. The entire time high blood pressure is working against your heart and arteries, you are completely unaware that it is causing so much damage. Not only does elevated or high blood pressure cause hardening of the arteries, which can lead to heart attack and other serious problems, but hypertension can result in a brain hemorrhage (stroke). Hypertension also causes kidney disease, where the kidneys function poorly. In some cases, hypertension can result in blindness and amputation of the limbs.