High Blood Pressure (Hypertension)

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What is high blood pressure?

Blood pressure is the force blood exerts on the walls of arteries as it flows through them; so, high blood pressure is when blood flows with too much force. It is a very common condition, affecting about 75 million Americans. This translates to 1 in 3 people in the United States. Unfortunately, many people do not know they have it. Hypertension is the medical name for high blood pressure.

A blood pressure measurement has two numbers with the units of pressure, mm Hg (millimeters of mercury). The top number is systolic pressure. It is the highest pressure in your arteries as the heart is pumping blood. The bottom number is diastolic pressure. It reflects the lowest pressure in your arteries when the heart is at rest, between beats. Normal blood pressure is 120/80 mm Hg or lower.

Categories of high blood pressure include:

  • Elevated blood pressure: a systolic reading of 120-129 mm Hg with a diastolic reading under 80 mm Hg. Left untreated, this category, also known as prehypertension, will likely worsen with time.

  • Stage I hypertension: a systolic reading of 130-139 mm Hg or a diastolic reading of 80-89 mm Hg

  • Stage II hypertension: a systolic reading of 140 mm Hg or higher or a diastolic reading of 90 mm Hg or higher

  • Hypertensive crisis: a systolic reading higher than 180 mm Hg or a diastolic reading higher than 120 mm Hg. This category requires immediate medical care.

Blood pressure varies naturally and can moderately rise and fall in response to many situations. For example, blood pressure will rise during strenuous activity or in stressful situations. Blood pressure is normally lower during periods of relaxation or sleep. Because of this, one high blood pressure reading does not mean you have hypertension. A high blood pressure diagnosis requires at least three high readings at different times. Ideally, these readings should take place at least one minute apart while you are resting.

Chronic, uncontrolled high blood pressure is a serious condition. It can lead to and complicate many health problems, including heart disease, kidney failure, and stroke. It is often called ‘the silent killer’ because it generally has no symptoms until serious complications develop.

Extremely high blood pressure that occurs suddenly or the long-term effects of mild to moderately high blood pressure over time can lead to life-threatening complications, such as stroke, kidney failure, and heart attack. Seek regular medical care to check for and promptly treat high blood pressure to reduce the risk of complications.

Seek immediate medical care (call 911) if you, or someone you are with, have symptoms such as chest pain, passing out, difficulty breathing, confusion, slurred speech, severe headache, or problems with moving any part of the body.

What are the symptoms of high blood pressure?

High blood pressure usually does not cause any symptoms. The only way to diagnose it is to measure it. This is why it is often called ‘the silent killer.’ Many people do not realize they have it until serious complications develop. In some cases, people with high blood pressure may experience nosebleeds or headaches.

Serious symptoms that might indicate a life-threatening condition

In some cases, high blood pressure can be life threatening, such as hypertensive crisis. High blood pressure can also accompany symptoms indicating a serious or life-threatening condition that needs immediate evaluation in an emergency setting. Seek immediate medical care (call 911) if you, or someone you are with, have any of these symptoms including:

Regular medical care can help find high blood pressure before serious problems develop. If you have high blood pressure, seeing your doctor on a regular basis is also important. Your doctor will likely have you monitor your blood pressure at home. But regular medical care can help identify early signs of potential complications.

What causes high blood pressure?

In most cases, high blood pressure has no known direct cause. This is primary—or essential—hypertension. It usually develops slowly over the course of time. Instead of a direct cause, there are indirect causes, such as age-related changes in blood vessels, various lifestyle habits, and genetic predisposition.

High blood pressure can also develop due to an underlying condition or medication. This is secondary hypertension. It tends to occur more suddenly than primary hypertension.

Common conditions that can cause secondary hypertension include kidney problems, thyroid disorders, and adrenal gland tumors. Obstructive sleep apnea can also contribute to high blood pressure.

Medications that can lead to high blood pressure include hormonal birth control, cold medicines, corticosteroids, and NSAIDs (nonsteroidal anti-inflammatory drugs). Cocaine and methamphetamine can also cause it.

What are the risk factors for high blood pressure?

High blood pressure is linked to several risk factors. However, not all people who are at risk for high blood pressure will develop it. And not all people who develop high blood pressure have risk factors. Risk factors include:

  • Age: High blood pressure becomes more common as you age.

  • Family history of high blood pressure

  • Gender: Males have a higher risk until age 64. After age 65, the risk is higher in females.

  • Other medical conditions: Diabetes, high cholesterol, anxiety, stress and prehypertension—or elevated blood pressure all increase the risk.

  • Race: High blood pressure is more common in African Americans. It tends to develop at a younger age and results in more serious complications, such as heart attack, in this group.

Lifestyle habits and behaviors can also increase the risk of high blood pressure. This includes being obese, smoking or using nicotine, leading a sedentary lifestyle, using alcohol excessively, and eating a high-salt diet.

Reducing your risk of high blood pressure

Changing risk factors you can control is the main way to reduce your risk of high blood pressure. There are several healthy behaviors you can adopt to reduce your risk of high blood pressure, including:

  • Eating a healthy diet low in salt and high in fiber, whole grains, and fresh fruits and vegetables

  • Getting regular physical exercise with 30 minutes of moderate-intensity activities five days a week

  • Limiting alcohol

  • Maintaining a healthy weight

  • Managing stress

  • Stopping smoking or using other forms of nicotine

It’s also important to seek regular medical care for other medical conditions that contribute to high blood pressure.

How is high blood pressure treated?

High blood pressure treatment involves a multifaceted approach. Doctors customize treatment plans based on the type and severity of high blood pressure, risk factors, lifestyle, and medical history. Your blood pressure goal will depend on your age and overall health.

The first step in treating high blood pressure is often the same lifestyle changes that can reduce your risk. These changes may be enough to bring elevated blood pressure—or prehypertension—under control. But sometimes lifestyle changes are not enough to lower blood pressure. When this is the case, doctors prescribe medications to lower blood pressure.

The type of medication that is best for you depends on how high your blood pressure is and your other medical conditions. Types high blood pressure medications include:

  • ACE (angiotensin-converting enzyme) inhibitors, which lower blood pressure by preventing the body from making angiotensin II, a hormone that narrows and tightens blood vessels. These drugs may be particularly helpful for people with kidney disease.

  • Alpha blockers, which decrease nerve impulses that tighten blood vessels

  • ARBs (angiotensin II receptor blockers), which block the action of angiotensin II. Like ACE inhibitors, people with kidney disease may benefit from an ARB.

  • Beta blockers, which lower blood pressure by helping the heart to beat more slowly and less forcefully

  • Calcium channel blockers, which relax the blood vessels. These drugs may work better than other high blood pressure medicines in African Americans and older people.

  • Centrally-acting agents, which work in the brain to prevent signals that narrow the blood vessels

  • Diuretics, which lower blood pressure by stimulating the kidneys to flush extra fluid and salt from the body. “Water pills” is a common name for these drugs. They are often the first choice for treating high blood pressure. Like calcium channel blockers, they may work better than other options in African Americans and the elderly.

  • Renin inhibitors, which decrease the production of renin, the enzyme that starts the chain reaction that makes angiotensin II

  • Vasodilators, which relax and widen blood vessels

You may start out on one medicine, but it is common to need a combination of medicines to effectively control blood pressure. It can take time to find the right medicine or combination of medicines for you. It involves some trial and error to adjust dosages or change medicines.

If an underlying condition is the root of the problem, doctors will address its treatment. When a medication is responsible for high blood pressure, your doctor may stop it or lower the dose.

What are the possible complications of high blood pressure?

When doctors find high blood pressure early, treatment is usually successful in preventing serious complications. However, uncontrolled high blood pressure can result in serious and even life-threatening complications. It can permanently damage the arteries throughout your body, including those that supply blood to vital organs, such as the kidneys, brain and heart.

Complications of uncontrolled high blood pressure include:

Following the treatment plan you and your doctor design offers the best chance of preventing complications from high blood pressure.

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2019 Aug 31
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