Your blood pressure should normally be less than 120/80 mm Hg if you are an adult age 20 or over. Some people think that those with high blood pressure are tense, nervous or hyperactive, but that is not true. You can be a calm, relaxed person and still have high blood pressure.
Healthy arteries are made of muscle and tissue that stretches like elastic when the heart pumps blood through them. The more forcefully your heart pumps, the more the arteries stretch to allow blood to flow. Over time, with a high force of blood flow, the walls of the arteries get stretched beyond a healthy limit and are damaged. This creates the following problems:
Overstretching due to high blood pressure creates weak places in the blood vessels, making them more prone to rupture. Hemorrhagic strokes and aneurysms are caused by ruptures in the blood vessels.
Tiny tears form in the blood vessels that leave scar tissue on the walls of the arteries. These tears and the scar tissue are like nets that catch debris such as cholesterol and blood cells traveling in the bloodstream.
Blood clots form due to trapped blood and further narrow or block the arteries. These clots sometimes break off and travel in the arteries to a different part of the body. This leads to strokes or damage to the organ where the clots end up.
Cholesterol and plaque build-up at the damaged sites in the arteries cause the blood flow to become less or even stop completely. Heart attacks and strokes occur with complete blockage of the arteries in the heart or the brain.
When the arteries are not as elastic because of the build-up of cholesterol or plaque or because of scarring, the heart pumps harder to get blood into the arteries. Over time, this increased work can result in damage to the heart itself. The muscles and valves in the heart can become damaged and heart failure is the end result.
You may not feel that anything is wrong, but high blood pressure can permanently damage your heart, brain, eyes and kidneys before you feel anything. Yes, uncontrolled high blood pressure can injure or kill you. It's often called "the silent killer" because high blood pressure has no symptoms.