High blood pressure, also known as hypertension, is the most common cardiovascular disease.

If you have high blood pressure, you'll probably find out about it during a routine checkup. Or, you may have noticed a problem while taking your own blood pressure. But be sure to see your doctor for a definite diagnosis, and take the opportunity to learn what you can do to bring your blood pressure under control.
Blood pressure refers to the force of blood pushing against artery walls as it courses through the body. Like air in a tire or water in a hose, blood fills arteries to a certain capacity. Just as too much air pressure can damage a tire or too much water pushing through a garden hose can damage the hose, high blood pressure can threaten healthy arteries and lead to life-threatening conditions such as heart disease and stroke.
Hypertension is the leading cause of stroke and a major cause of heart attack. In the United States alone, approximately 73 million people have high blood pressure.

WebMD. (2009, December 06). Retrieved from http://www.webmd.com/hypertension-high-blood-pressure/guide/understanding-high-blood-pressure-basics