Hypertension, also referred to as high blood pressure, is a condition in which the arteries have persistently elevated blood pressure. Every time the human heart beats, it pumps blood to the whole body through the arteries.
Blood pressure is the force of blood pushing up against the blood vessel walls. The higher the pressure the harder the heart has to pump.
Hypertension can lead to damaged organs, as well as several illnesses, such as renal failure (kidney failure), aneurysm, heart failure, stroke, or heart attack.
[Quoted from: http://www.medicalnewstoday.com/articles/150109.php]