Understanding Hypertension
Hypertension, or high blood pressure, is when your blood pressure is higher than normal for an extended period of time. The condition is asymptomatic except in very serious cases. Normal blood pressure is less than 120 (systolic) over 80 (diastolic)—often written as 120/80 mm Hg (read 120 over 80 millimeters of mercury). Your doctor should measure your blood pressure during each visit. If your doctor finds that your blood pressure is consistently higher after several visits, you may be diagnosed with hypertension.
If you have recently been diagnosed with hypertension (high blood pressure) you should take it seriously, but there are positive steps you can take. While high blood pressure is a serious condition, there are many lifestyle changes and treatment options available to help lower blood pressure.
The odds are good that most people will have high blood pressure in their lifetime. In fact, more than 73 million American adults have high blood pressure.1 Approximately 90% of people with normal blood pressure at age 55 will develop high blood pressure as they get older.2 However, it’s important to know that even though high blood pressure is quite common, it is still a dangerous condition that should be monitored closely by a doctor.
Disease Stages
Normal blood pressure is less than 120/80. When a person has a blood pressure reading between 120/80 and 139/89, this condition is called prehypertension. Stage 1 hypertension is defined as 140-159 over 90-99, and a blood pressure above those levels is considered Stage 2 hypertension.3
The Stages of Hypertension
| Blood pressure (mm Hg) |
Stage |
| Less than 120/80 |
Normal |
| 120/80 to 139/89 |
Prehypertension |
| 140/90 to 159/99 |
Stage 1 hypertension |
| 160/100 and higher |
Stage 2 hypertension |
Diagnosis
During a regular physical exam, a doctor or other healthcare provider uses a sphygmomanometer (blood pressure cuff) to check blood pressure. This common device should be familiar to you: it consists of a cuff that fastens around the upper arm and is attached to a bulb. The doctor inflates the cuff by squeezing the bulb. The doctor then releases the air from the cuff and listens with a stethoscope for the first heartbeat that can be heard. The pressure at which the first heartbeat is heard is called systolic blood pressure. The pressure at which the doctor can no longer hear the heart sound is called diastolic blood pressure.2
Your doctor may also check for hypertensive retinopathy, which is damage to the blood vessels in the eyes caused by high blood pressure. Since high blood pressure puts people at risk for stroke and kidney failure, the exam will also cover all of the major organs, such as the brain, lungs, and kidneys, to check for damage. Depending on the results of these tests, more tests (e.g., urinalysis, blood tests, and ECG) may be necessary.2,3
Prognosis
If high blood pressure is well controlled, most serious complications may be avoidable. However, for people with very high, uncontrolled blood pressure combined with retinopathy, serious problems could develop. Coronary artery disease and stroke are the most common causes of death for people with very serious high blood pressure. Talking to your doctor and taking steps now to lower blood pressure are the best ways to prevent more serious problems from developing.3
Next: How is your blood pressure measured?
References: 1. American Heart Association. Heart Disease and Stroke Statistics 2009 Update: A Report From the American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Available at: http://circ.ahajournals.org/cgi/content/full/119/2/e21. Accessed: May 14, 2009. 2. Merck Research Laboratories. The Merck Manual of Diagnosis and Therapy. 18th ed. Whitehouse Station, NJ. Merck & Co., Inc., 2006. 3. National Institutes of Health. National Heart, Lung, and Blood Institute. Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7). May 2003. NIH Publication No. 03-5233.
