Hypertension (HTN), also known as high blood pressure, is defined as an upper number blood pressure reading greater that 140 or a lower number blood pressure reading greater than 90.

Blood is carried from the heart to all of your body’s tissues and organs in vessels called arteries. Blood pressure is the force of the blood pushing against the walls of those arteries. Blood pressure is divided into two readings. The systolic blood pressure is the top number of a blood pressure reading. This shows the force of the contraction of the heart. The diastolic blood pressure is the bottom number of a blood pressure reading. It shows the pressure in the blood vessels between heartbeats and the tone or condition of the blood vessels.

What controls blood pressure?
The heart, blood vessels, brain and kidneys control blood pressure. Blood pressure is also controlled by the amount of fluid and salt in the body. Certain hormones in the body can affect the condition of blood vessels as well as body fluids. The force of the contraction of the heart can also affect blood pressure.

What are the signs and symptoms of HTN?
In most cases there are no symptoms of high blood pressure. However, after a long time, people may develop: headaches, chest pain, shortness of breath, and vision changes.

Who is more likely to develop HTN?
Anyone can develop HTN, but some people are more likely to develop it than others. For example, HTN is more common—it develops earlier and is more severe—in African-Americans. In the early and middle adult years, men have HTN more often than women. But as men and women age, the reverse is true. More women after menopause have high blood pressure than men of the same age. And the number of both men and women with HTN increases rapidly in older age groups. For example, older African-American women who live in the Southeast are more likely to have HTN than those in other regions of the United States. In fact, the southeastern states have some of the highest rates of death from stroke. HTN is the key risk factor for stroke.

The cause of 90-95% HTN is unknown and is called essential HTN. In some cases, HTN is caused by kidney, heart or hormone problems. Some medications and excessive alcohol use can also cause HTN. Finally, heredity can make some individuals more likely than others to get HTN. If your parents or grandparents had HTN, your risk may be increased. Getting your blood pressure checked regularly is the best way tot monitor for HTN.

What can be done to prevent HTN?
Maintaining a healthy body weight, including physical activity in everyday life, and eating a low-fat, low-cholesterol, low-sodium diet are lifestyle changes that can help avoid or reduce HTN. Even with these lifestyle changes many cases of HTN cannot be prevented.

What are the long-term effects of HTN?
HTN harms the arteries by making them thick and stiff. This speeds the build up of cholesterol and fats in the blood vessels like rust in a pipe, which prevents the blood from flowing through the body, and in time can lead to a heart attack or stroke. HTN causes the heart to work harder. Over time, this causes the heart to thicken and stretch. Eventually the heart fails to function normally causing fluids to back up into the lungs. Over a number of years, HTN can narrow and thicken the blood vessels of the kidney. The kidney filters less fluid, and waste builds up in the blood. The kidneys may fail altogether. When this happens, medical treatment (dialysis) or a kidney transplant may be needed. There can also be blood vessel damage to the eye.

How is HTN diagnosed?
The diagnosis is made on the basis of several blood pressure readings. Blood tests and other tests may also be done to make sure there is not an obvious cause for the HTN.

What are the treatments?
There are many medications used to treat HTN. Some of the drugs include diuretics, beta blockers, calcium channel blockers, angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, vasodilators and centrally acting nervous system medications.

What are the side effects of treatment?
Beta-blockers can worsen asthma. Diuretics may cause a loss of too much fluid and minerals. Calcium channel blockers can cause swelling of the legs called edema. ACE inhibitors may lead to chronic dry cough. Overall, most HTN medicines are well tolerated. Side effects should be discussed with the healthcare provider.