Hypertension — also known as high blood pressure — affects nearly one in three adults, and two of every three persons age 65 or over, in the U.S.
High blood pressure is called "the silent killer" because it has no symptoms. Left untreated over the long term, it can damage blood vessels throughout the body by stretching artery walls thin. As a result, high blood pressure can increase the risk of aneurysm — a swelling in an artery wall that can cause an artery to rupture.
Fortunately, high blood pressure is easy to detect and can be controlled with lifestyle changes. Successfully treating the condition — through proper nutrition, normal weight, regular exercise and, if necessary, medications — can also reduce stroke risk and heart attack risk.
What is Blood Pressure?
Blood pressure is a measurement of the force that blood exerts upon artery walls as it's pumped throughout the body. The amount of blood pumped, as well as the size and flexibility of the arteries, are the key factors that determine blood pressure.
Blood pressure readings have two numbers:
- Systolic pressure, the "top" number, is a measurement of pressure as the heart contracts, to pump blood. A normal, healthy number is less than 120.
- Diastolic pressure, the "bottom" number, is a measurement of pressure when the heart relaxes and is re-filled with blood. A normal, healthy number is less than 80.
- A patient with a reading of 115 over 75 is said to have normal blood pressure.
- As blood pressure rises over normal readings, health risk increases. High blood pressure is a systolic reading of 140 (or higher) and a diastolic reading of 90 (or higher) taken over time.
Keep in mind that blood pressure changes continually — even during the course of the day. Early-morning readings are highest. Cold temperatures, emotional stress, coffee, tobacco use and exercise also can elevate blood pressure.
Symptoms of High Blood Pressure
Because high blood pressure typically does not have symptoms, most individuals with high blood pressure — even dangerously high blood pressure levels — are unaware they have it.
In rare circumstances, those with early-stage high blood pressure may experience dull headaches, nausea, dizziness or nosebleed. However, symptoms such as these are only occasionally felt by those with advanced hypertension.
Causes and Risk Factors
The exact causes of high blood pressure are not known. However, several risk factors are closely linked with the condition:
- Race: African-Americans are at higher risk.
- Family history of hypertension.
- Being overweight or obese.
- Tobacco use.
- Drinking alcohol in excess.
- Not getting enough exercise.
- High sodium (salt) intake.
- Low potassium intake.
- Low vitamin D intake.
- Chronic conditions: Diabetes, high cholesterol, kidney disease and sleep apnea.
Preventing and Managing High Blood Pressure
The objective of hypertension treatment is to reduce the risk of complications related to the condition — namely, heart disease and stroke. Ideally, that means reducing blood pressure to 120/80 mm Hg, but even a partial lowering of blood pressure brings benefits.
The following actions can help lower blood pressure:
- Maintaining a proper weight: Being overweight is one of the strongest predictors of developing high blood pressure. Having a weight in a normal range is one of the most effective methods to prevent hypertension.
- Reducing salt intake: As sodium builds in the bloodstream, water collects in the blood vessels; blood pressure rises and the heart must work harder to pump blood. Therefore, limiting sodium intake to 2,400 mg per day — one level teaspoon — can help lower blood pressure.
- Increasing physical activity: Sedentary people may be at higher risk for developing hypertension. Aim for at least 30 minutes of moderate exercise — such as walking — every day.
- Limiting alcohol consumption: Consuming three or more alcoholic beverages per day increases hypertension risk. Men should consume no more than two drinks per day; women should have no more than one drink per day.
- Eating a diet rich in fruits and vegetables: The Dietary Approaches to Stop Hypertension (DASH) diet, recommends eating four to five servings of fruits and vegetables each per day to keep blood pressure under control.
If the above lifestyle changes don't reverse high blood pressure, some patients — particularly those with systolic pressure above 160 mm/HG or diastolic pressure above 100 mm/HG — may require prescription medications.
Commonly prescribed medications include:
- Diuretics, which help the kidneys remove sodium and water from the body. Doing so decreases the body's overall blood volume.
- Beta blockers, which slow the heart rate and reduce the heart's workload. Beta blockers also reduce stress hormones in the body, helping the blood vessels open and improving blood flow.
- ACE inhibitors (angiotensin-converting enzyme inhibitors), which block the chemical angiotensin, a hormone that causes the blood vessels to tighten and make the heart work harder. Some patients may be prescribed ARBs: angiotensin II receptor blockers.
- Calcium-channel blockers, which relax blood vessels and lower blood pressure by blocking calcium from entering heart cells and arteries.