What is high blood pressure?

High Blood Pressure¹ (hypertension) is a chronic condition in which the force of the blood against your arteries’ walls is high enough that it may be harmful to your long-term health. Ongoing hypertension can cause health problems such as heart disease² and can affect the overall health of your heart and other organs.

High blood pressure generally develops over many years and can be present for a long time without noticeable symptoms. Even when asymptomatic, however, high blood pressure can continue to damage the heart and blood vessels at detectable levels.

Your blood pressure is determined by two factors: 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 will be.

How common is high blood pressure?

High blood pressure is extremely common³. The American Heart Association reported⁴ in 2013 that about 77.9 million (1 of 3) adults in the United States had high blood pressure. The AHA cited data from NHANES (2007–10) which showed that of U.S. adults with high blood pressure, roughly 81.5% were aware that they have it.

The prevalence of high blood pressure was found to be the highest among non-Hispanic blacks, of which 42.6% of men and 47% of women suffered from the conditions.

High blood pressure was listed as a primary or contributing factor in more than 410,000 deaths⁵ in 2014. Furthermore, having high blood pressure puts you at risk for developing heart disease and stroke⁶, both of which are leading causes of death in the United States.

What is pulmonary hypertension?

Pulmonary hypertension⁷ is a type of high blood pressure that affects the arteries in the lungs and the muscles in the right side of the heart. When these blood vessels become constricted or blocked, your heart has to work much harder to pump blood through them.

In one form of pulmonary hypertension, pulmonary arterioles (tiny arteries in the lungs) and capillaries become narrowed, blocked, or destroyed, making it harder for blood to flow through the lungs and raising the pressure within the lungs’ arteries.

As this pressure builds, the right ventricle (the heart’s lower right-side chamber) must work harder to pump blood through the lungs. This causes the heart muscle to weaken, potentially causing congestive heart failure⁸.

There are multiple forms of pulmonary hypertension. These forms are classified into five groups, each depending on their cases. These groups are:

• Pulmonary arterial hypertension: This form of pulmonary arterial hypertension can be caused by a number of conditions, such as congenital heart defects⁹ and gene mutations. This also includes idiopathic¹⁰ pulmonary arterial hypertension, which denotes that a cause for the condition is unknown.

• Pulmonary hypertension caused by left-sided heart disease: As its name states, this group refers to pulmonary hypertension caused by left-sided valvular heart disease (such as mitral valve disease¹¹ or aortic valve disease¹²) or failure of the left ventricle (lower left heart chamber).

• Pulmonary hypertension caused by lung disease: This condition can be caused by lung diseases such as chronic obstructive pulmonary disease¹³ (COPD), emphysema¹⁴, or pulmonary fibrosis¹⁵. Other causes include sleep disorders (such as sleep apnea¹⁶) and long-term exposure to high altitudes (in people who may be at a higher risk for developing pulmonary hypertension).

• Pulmonary hypertension caused by chronic blood clots: This form of pulmonary hypertension is caused by chronic blood clots in the lungs (called pulmonary emboli¹⁷).

• Pulmonary hypertension associated with other conditions: This group refers to pulmonary hypertension caused by a variety of other conditions, including blood disorders¹⁸, disorders that affect several organs (such as sarcoidosis¹⁹), metabolic disorders (such as glycogen storage disease²⁰), and tumors that press against pulmonary arteries. Some forms of pulmonary hypertension are serious and become progressively worse (and, in some cases, fatal). While some forms of this condition are incurable, receiving medical treatment and carefully monitoring the condition can help improve symptoms and quality of life.

Like other forms of hypertension, pulmonary hypertension can go unnoticed for years because the weakening heart muscle doesn’t trigger any obvious symptoms. If detected early enough, pulmonary hypertension can be managed with the help of your doctor.

High blood pressure causes

Many adults develop essential hypertension²¹. Also called primary hypertension, this form of high blood pressure develops slowly over the course of your life and may not be noticed for years. There is no known cause²² of primary hypertension.

High blood pressure is often the symptom of one or more underlying conditions. When this is the case, the condition is referred to as secondary hypertension. Secondary hypertension is generally quicker to onset and more sudden than primary hypertension.

Some of the causes of secondary hypertension include:

• Obstructive sleep apnea
• ²³Kidney problems

• Adrenal gland tumors
• Thyroid problems
• Certain congenital (present at birth) defects in blood vessels
• Diabetes²⁴

• Lupus²⁵, an autoimmune disorder that can cause serious damage to the cardiovascular system Some prescription drugs and over-the-counter medications can also raise your blood pressure and increase your risk of hypertension. These include:

• Hormonal contraceptive pills, especially those containing higher doses of estrogen
• Certain antidepressants, including SSRIs (selective serotonin reuptake inhibitors)
• Corticosteroids
• Nonsteroidal anti-inflammatory drugs (NSAIDs), often sold over the counter for pain relief
• Decongestants, such as phenylephrine and pseudoephedrine
• Stimulants, such as methylphenidate and amphetamines
• Illicit drugs, such as methamphetamines and cocaine

Risk factors for high blood pressure

Some lifestyle factors, pre-existing conditions, and genetics may raise your risk of developing high blood pressure²⁶. These risk factors include:

• Age: As you grow older, your blood pressure tends to rise. Older people, therefore, have a higher risk of developing high blood pressure.
• Ethnicity: Research has found that African Americans are likely to develop high blood pressure at higher rates, and earlier in life, than other groups.
• Family history: There may be genetic factors that affect the risk of high blood pressure. A family history of high blood pressure may indicate a greater risk.
• Diet: Consuming too much sodium due to a high-salt diet increases the risk of high blood pressure.
• Weight and activity: Being overweight or obese is a risk factor for high blood pressure. A sedentary lifestyle is also correlated with weight gain and high blood pressure.
• Tobacco: Smoking damages the heart and blood vessels, while the nicotine in all tobacco products raises blood pressure.
• Alcohol: Alcohol²⁷ increases your risk of high blood pressure by raising your blood pressure. The Centers for Disease Control and Prevention recommend that men, on average, have no more than 1–2 drinks per day, and that women have no more than 1 drink per day.

High blood pressure symptoms

In some cases, people with high blood pressure may experience headaches, shortness of breath, or nosebleeds. These signs and symptoms aren’t specific to high blood pressure, however, and usually don’t occur until the condition has reached a severe or life-threatening stage.

Because high blood pressure does not always present obvious symptoms, it can be difficult to determine whether you have high blood pressure without testing for the condition. It’s important to ask your healthcare provider to test your blood pressure as part of your routine medical visits.

In the case of pulmonary hypertension, there are a few additional warning signs. These include:

• Fatigue: feeling unusually tired can be a sign that your body is having to work too hard to pump blood, which could indicate pulmonary hypertension
• Chest pain: Pain in the heart itself can indicate excessive blood pressure or weakening heart muscles.
• Swollen ankles (edema): Edema is caused by blood pooling in the lower parts of your body. This can happen when your body isn’t strong enough to push the blood upwards against gravity.
• Cyanosis: This condition, where the face, lips, or other extremities turn blue, is a sign that your blood has a low concentration of oxygen. This might be a clue that you have pulmonary hypertension.