Approximately one in three adults in the United States has been diagnosed with high blood pressure, or hypertension — often called “the silent killer” because it presents no symptoms. In fact, many individuals unknowingly endure hypertension for years and, as a result, risk for developing more serious health problems. The only way to know if you’re one of them is to have your blood pressure tested.

Blood pressure is a measure of the amount of blood your heart pumps and the amount of resistance to blood flow in your arteries. The more blood your heart pumps and the narrower your arteries, the higher your blood pressure. Blood pressure is measured in two sets of numbers: Systolic pressure, or the higher number, is the pressure the heart generates to pump blood through the rest of the body; diastolic pressure, or the lower number, is the pressure in the blood vessels between heartbeats.

Current guidelines suggest a Bp of 120/70–80 or less is normal. Individuals with a systolic Bp between 120 and 139 or a diastolic pressure between 80 and 89 are considered pre-hypertensive. Those with higher pressure fall into one of two stages: stage 1, with a systolic Bp between 140 and 159 or diastolic Bp between 90 and 99; or stage 2, with a systolic Bp greater than 160 or diastolic Bp greater than 100.

Although hypertension usually presents no symptoms, very high pressure can cause dull headaches, ringing in the ears, dizziness, fatigue or nosebleeds. Uncontrolled high blood pressure can lead to stroke, heart attack, heart disease or kidney failure, and can also cause damage to the brain, eyes and arteries. Hypertension was listed as a primary or contributing cause of more than 300,000 American deaths in 2004.

Some chronic conditions — such as diabetes, high cholesterol, sleep apnea and renal disease — can increase your risk of developing high blood pressure. But most healthy individuals can make simple lifestyle changes to lessen their risk or reduce elevated blood pressure.

The first step is to be aware of the risk factors that are within your control:

• Extra Weight The more you weigh, the more blood you need to supply oxygen to the tissues; the increased volume of blood increases the pressure on the walls of the arteries.

• Physical Inactivity People who are inactive have higher heart rates, increasing the heart’s workload and the pressure on the arteries.

• Vitamins and Minerals Sodium causes the body to retain fluid and increases blood pressure. Potassium helps to balance the amount of sodium in the body. Researchers are studying the relationship between Vitamin D and kidney function and its effect on blood pressure.

• Tobacco Products Tobacco immediately raises your blood pressure; chemicals in tobacco can damage the lining of artery walls, making them narrow and increasing blood pressure.

• Alcohol Having two or three drinks at one sitting can raise your blood pressure; alcohol also releases hormones to increase your blood flow and heart rate.

• Stress High levels of stress can cause temporary but dramatic increases in blood pressure. Eating too much food, drinking alcohol or smoking to relax and cope with stress will only increase your blood pressure.

People with high blood pressure can live healthy and happy lives through the proper use of prescribed medication and lifestyle changes. Testing your blood pressure at home with a monitor is helpful — many monitors will record and store the readings, making it easy to share the information with your doctor as you discuss your plan of care.

Be sure to pack enough medication when traveling and keep it in your carry-on. Include extra doses in case you decide to extend your travel. If you self-monitor your pressure, you can fax or email your readings to your doctor while you are away. Make sure the blood pressure monitor you purchase is easy to use, is rated well for at-home and travel use and has a cuff that fits your upper arm.

The DASH (Dietary Approaches to Stop Hypertension) eating plan, clinically proven to reduce blood pressure, can help you track your sodium intake and point you toward healthier eating. For more information, visit http://www.nhlbi.nih.gov/health/public/heart/hbp/dash.

Steady Your Pressure

• Have your blood pressure checked frequently.
• Maintain a healthy weight.
• Stay active — even short walks can help.
• Limit use of salt in cooking and at meals.
• Avoid salty processed foods and snacks; read labels.
• Eat fresh fruits, vegetables and whole-grain, high-fiber foods.
• Limit or quit tobacco use.
• Limit alcohol intake to one drink a day for women, two for men.