Pulmonary hypertension is a type of high blood pressure that affects the arteries in the lungs and the right side of the heart.

In one form of pulmonary hypertension, called pulmonary arterial hypertension (PAH), blood vessels in the lungs are narrowed, blocked or destroyed. The damage slows blood flow through the lungs, and blood pressure in the lung arteries rises. The heart must work harder to pump blood through the lungs. The extra effort eventually causes the heart muscle to become weak and fail.

In some people, pulmonary hypertension slowly gets worse and can be life-threatening. Although there's no cure for some types of pulmonary hypertension, treatment can help reduce symptoms and improve quality of life.

The signs and symptoms of pulmonary hypertension develop slowly. You may not notice them for months or even years. Symptoms get worse as the disease progresses.

Pulmonary hypertension signs and symptoms include:

• Shortness of breath (dyspnea), initially while exercising and eventually while at rest
• Fatigue
• Dizziness or fainting spells (syncope)
• Chest pressure or pain
• Swelling (edema) in the ankles, legs and eventually the abdomen (ascites)
• Bluish color to the lips and skin (cyanosis)
• Fast pulse or pounding heartbeat (palpitations)

The typical heart has two upper chambers (atria) and two lower chambers (ventricles). Each time blood passes through the heart, the lower right chamber (right ventricle) pumps blood to the lungs through a large blood vessel (pulmonary artery).

In the lungs, the blood releases carbon dioxide and picks up oxygen. The blood typically flows easily through blood vessels in the lungs (pulmonary arteries, capillaries and veins) to the left side of the heart.

However, changes in the cells that line the pulmonary arteries can cause the walls of the arteries to become stiff, swollen and thick. These changes may slow down or block blood flow through the lungs, causing pulmonary hypertension.

Pulmonary hypertension is classified into five groups, depending on the cause.

Group 1: Pulmonary arterial hypertension (PAH)

Causes include:

• Unknown cause (idiopathic pulmonary arterial hypertension)
• Changes in a gene passed down through families (heritable pulmonary arterial hypertension)
• Use of some prescription diet drugs or illegal drugs, such as meth
• Heart problems present at birth (congenital heart disease)
• Other conditions such as HIV infection, chronic liver disease (cirrhosis) and connective tissue disorders (scleroderma, lupus, others)

Group 2: Pulmonary hypertension caused by left-sided heart disease

Causes include:

• Left-sided heart valve disease such as mitral valve or aortic valve disease
• Failure of the lower left heart chamber (left ventricle)

Group 3: Pulmonary hypertension caused by lung disease

Causes include:

• Chronic obstructive pulmonary disease (COPD)
• Scarring of the tissue between the lung's air sacs (pulmonary fibrosis)
• Obstructive sleep apnea
• Long-term exposure to high altitudes in people who may be at higher risk of pulmonary hypertension

Group 4: Pulmonary hypertension caused by chronic blood clots

Causes include:

• Chronic blood clots in the lungs (pulmonary emboli)
• Other clotting disorders

Group 5: Pulmonary hypertension triggered by other health conditions

Causes include:

• Blood disorders, including polycythemia vera and essential thrombocythemia
• Inflammatory disorders such as sarcoidosis and vasculitis
• Metabolic disorders, including glycogen storage disease
• Kidney disease
• Tumors pressing against pulmonary arteries

Eisenmenger syndrome and pulmonary hypertension

Eisenmenger syndrome is a type of congenital heart disease that causes pulmonary hypertension. It's most commonly caused by a large hole in the heart between the two lower heart chambers (ventricles), called a ventricular septal defect.

This hole in the heart causes blood to flow incorrectly in the heart. Oxygen-carrying blood (red blood) mixes with oxygen-poor blood (blue blood). The blood then returns to the lungs — instead of going to the rest of the body — increasing the pressure in the pulmonary arteries and causing pulmonary hypertension.

Pulmonary hypertension is more often diagnosed in people ages 30 to 60. Growing older can increase the risk of developing pulmonary arterial hypertension (PAH). However, idiopathic PAH is more common in younger adults.

Other things that can raise the risk of pulmonary hypertension include:

• A family history of the condition
• Being overweight
• Blood-clotting disorders or a family history of blood clots in the lungs
• Exposure to asbestos
• Congenital heart disease
• Living at a high altitude
• Use of certain weight-loss drugs
• Use of illegal drugs such as cocaine
• Use of selective serotonin reuptake inhibitors (SSRIs), used to treat depression and anxiety

Potential complications of pulmonary hypertension include:

• Right-sided heart enlargement and heart failure (cor pulmonale). In cor pulmonale, the heart's right ventricle becomes enlarged and has to pump harder than usual to move blood through narrowed or blocked pulmonary arteries.

  As a result, the heart walls thicken and the right ventricle expands to increase the amount of blood it can hold. But these changes create more strain on the heart, and eventually the right ventricle fails.

• Blood clots. Having pulmonary hypertension increases the risk of blood clots in the small arteries in the lungs.
• Arrhythmia. Pulmonary hypertension can cause irregular heartbeats (arrhythmias), which can lead to a pounding heartbeat (palpitations), dizziness or fainting. Certain arrhythmias can be life-threatening.
• Bleeding in the lungs. Pulmonary hypertension can lead to life-threatening bleeding into the lungs and coughing up blood (hemoptysis).
• Pregnancy complications. Pulmonary hypertension can be life-threatening for developing baby.

Pulmonary hypertension is hard to diagnose early because it's not often detected during a routine physical exam. Even when the condition is more advanced, its signs and symptoms are similar to those of other heart and lung conditions.

To diagnose pulmonary hypertension, a doctor will perform a physical exam and review any signs and symptoms. You'll likely be asked questions about your medical and family history.

Blood and imaging tests done to help diagnose pulmonary hypertension may include:

• Blood tests. Blood tests can help determine the cause of pulmonary hypertension or detect signs of complications.
• Chest X-ray. A chest X-ray creates pictures of the heart, lungs and chest. It can show enlargement of the right ventricle or the pulmonary arteries. A chest X-ray may also be used to check for other lung conditions that can cause pulmonary hypertension.
• Electrocardiogram (ECG). This noninvasive test shows the heart's electrical patterns and can detect abnormal heartbeats. An ECG may also reveal signs of right ventricle enlargement or strain.

• Echocardiogram. Sound waves are used to create moving images of the beating heart. An echocardiogram lets a doctor see how well the heart and its valves are working. It can show the size and thickness of the right ventricle and the pressure in the pulmonary arteries.

  Sometimes, an echocardiogram is done while exercising on a stationary bike or treadmill to understand how well the heart works during activity. If you have this test, you may be asked to wear a mask that checks how well the heart and lungs use oxygen and carbon dioxide.

  An echocardiogram may also be done after diagnosis to determine how well treatments are working.

• Right heart catheterization. If an echocardiogram reveals pulmonary hypertension, you'll likely have a right heart catheterization to confirm the diagnosis.

  During this procedure, a cardiologist places a thin, flexible tube (catheter) into a vein, usually in the groin. The catheter is gently guided into the right ventricle and pulmonary artery.

  Right heart catheterization allows a doctor to directly measure the pressure in the main pulmonary arteries and right ventricle of the heart. The test may also be used to determine how well pulmonary hypertension medications are working.

If you're diagnosed with pulmonary hypertension, your doctor might also order one or more of the following tests to check the condition of your lungs and pulmonary arteries and further determine the cause of the disease:

• Computerized tomography (CT). This imaging test creates cross-sectional pictures of the bones, blood vessels and soft tissues inside the body. A CT scan can show the size of the heart and any blockages in the pulmonary arteries. This test may be used to look more closely for lung diseases that might lead to pulmonary hypertension such as COPD or pulmonary fibrosis. A dye (contrast material) may be injected into a blood vessel before the CT scan to help the arteries show up more clearly on the images.
• Magnetic resonance imaging (MRI). An MRI scan uses a magnetic field and pulses of radio wave energy to make pictures of the body. A doctor may order this test to see blood flow in the pulmonary arteries and determine how well the right ventricle is working.
• Lung (pulmonary) function test. This noninvasive test measures how much air the lungs can hold and the airflow in and out of the lungs. The test involves blowing into an instrument called a spirometer.
• Sleep study (polysomnogram). This test measures brain activity, heart rate, blood pressure, oxygen levels and other factors during sleep. It can help diagnose a sleep disorder such as obstructive sleep apnea, which can cause pulmonary hypertension.
• Ventilation/perfusion (V/Q) scan. In this test, a tracer is injected into a vein in the arm. The tracer shows blood flow and airflow to the lungs. A V/Q scan can determine whether blood clots are causing symptoms of pulmonary hypertension.
• Open-lung biopsy. Rarely, a doctor might recommend an open-lung biopsy to check for a possible cause of pulmonary hypertension. An open-lung biopsy is a type of surgery in which a small sample of tissue is removed from the lungs.

Genetic testing

If a family member has had pulmonary hypertension, screening for genes that are linked with disease may be recommended. If you test positive, your doctor might recommend that other family members also be screened.

Pulmonary hypertension severity classification

Once a diagnosis of pulmonary hypertension is confirmed, a doctor will classify the severity of the disease into one of following categories:

• Class I. Pulmonary hypertension is diagnosed, but there are no symptoms during activity.
• Class II. There are no symptoms at rest, but symptoms such as fatigue, shortness of breath or chest pain occur with activity.
• Class III. It's comfortable at rest, but symptoms occur during physical activity.
• Class IV. Symptoms occur at rest and during physical activity.

There's no cure for pulmonary hypertension, but treatment is available to help improve signs and symptoms and slow the progress of the disease.

It often takes some time to find the most appropriate treatment for pulmonary hypertension. The treatments are often complex and require extensive follow-up care.

When pulmonary hypertension is caused by another condition, treatment is given for the underlying cause whenever possible.

Medications

Many different types of medications are available to help improve pulmonary hypertension signs and symptoms and slow disease progression, including:

• Blood vessel dilators (vasodilators). Vasodilators relax and open narrowed blood vessels, improving blood flow. A commonly prescribed vasodilator for pulmonary hypertension is epoprostenol (Flolan, Veletri).

  This drug continuously flows through an IV attached to a small pump, which is worn in a pack on the belt or shoulder. Potential side effects of epoprostenol include jaw pain, nausea, diarrhea, leg cramps, and pain and infection at the IV site.

  Other types of vasodilators, including treprostinil (Tyvaso, Remodulin, Orenitram), can be inhaled, injected or taken by mouth. The drug iloprost (Ventavis) is given while breathing in through a nebulizer, a machine that vaporizes the medication.

  Side effects associated with treprostinil include chest pain, often with headache and nausea, and breathlessness. Possible side effects of iloprost include headache, nausea and diarrhea.

• Guanylate cyclase (GSC) stimulators. This type of medicine increases nitric oxide in the body, which relaxes the pulmonary arteries and lowers pressure in the lungs. GSC stimulators include riociguat (Adempas). Side effects include nausea, dizziness and fainting. You should not take GSC stimulators if you're pregnant.
• Endothelin receptor antagonists. These medications reverse the effect of endothelin, a substance in the walls of blood vessels that causes them to narrow. Such drugs include bosentan (Tracleer), macitentan (Opsumit) and ambrisentan (Letairis). These drugs may improve energy level and symptoms. However, they can damage the liver. You may need monthly blood tests to check your liver function. Endothelin receptor antagonists shouldn't be taken during pregnancy.
• Sildenafil and tadalafil. Sildenafil (Revatio, Viagra) and tadalafil (Adcirca, Cialis, Alyq) are commonly used to treat erectile dysfunction. But they also open the blood vessels in the lungs and allow blood to flow through more easily. Side effects can include upset stomach, headache and vision problems.
• High-dose calcium channel blockers. These drugs help relax the muscles in the walls of your blood vessels. They include amlodipine (Norvasc), diltiazem (Cardizem, Tiazac, others) and nifedipine (Procardia). Although calcium channel blockers can be effective, only a small number of people with pulmonary hypertension improve while taking them.

• Warfarin (Jantoven). Warfarin is a blood thinner (anticoagulant). It may be prescribed to help prevent blood clots in the pulmonary arteries. Blood thinners increase the risk of bleeding, especially in those who are having surgery or an invasive procedure. If you take warfarin, talk to your doctor about whether you need to stop taking the medication before surgery and for how long.

  Many other drugs, herbal supplements and foods can interact with warfarin. Talk to your doctor about your diet and all the medications you take, including those bought without a prescription. People who take warfarin need occasional blood tests to check how well the medicine is working.

• Digoxin (Lanoxin). This medicine helps the heart beat stronger and pump more blood. It can help control irregular heartbeats (arrhythmias).
• Diuretics. Commonly known as water pills, these medications help the kidneys remove excess fluid from the body. This reduces the amount of work the heart has to do. Diuretics may also be used to reduce fluid buildup in the lungs, legs and abdomen.
• Oxygen therapy. Breathing pure oxygen is sometimes recommended as a treatment for pulmonary hypertension, especially for those who live at a high altitude or have sleep apnea. Continuous oxygen therapy may be needed.

Surgery and other procedures

If medications do not help control the signs and symptoms of pulmonary hypertension, surgery may be recommended. Surgeries to treat pulmonary hypertension include:

• Atrial septostomy. This open-heart surgery may be recommended if medications don't control pulmonary hypertension signs and symptoms. In an atrial septostomy, a surgeon creates an opening between the upper left and right chambers of the heart (atria) to relieve the pressure on the right side of the heart. Potential complications include heart rhythm problems (arrhythmias).

• Lung or heart-lung transplant. Sometimes, a lung or heart-lung transplant may be recommended, especially for younger people who have idiopathic pulmonary arterial hypertension.

  Major risks of any type of transplantation include rejection of the transplanted organ and serious infection. Immunosuppressant drugs must be taken for life to help reduce the chance of rejection.

Although medical treatment can't cure pulmonary hypertension, it can lessen symptoms. Lifestyle changes also may help improve your condition. Consider these tips:

• Get plenty of rest. Resting can reduce fatigue related to pulmonary hypertension.

• Stay as active as possible. Even the mildest forms of activity might be too exhausting for some people who have pulmonary hypertension. For others, moderate exercise, such as walking, might be beneficial — especially when done during oxygen therapy. But first, talk to your doctor about your specific exercise restrictions.

  Usually, it's recommended that people with pulmonary hypertension not lift heavy weights. Your doctor can help you plan an appropriate exercise program.

• Don't smoke. If you smoke, the most important thing you can do for your heart and lungs is to stop. If you can't stop smoking by yourself, ask your doctor to prescribe a treatment plan to help you quit. Also, avoid secondhand smoke if possible.
• Avoid pregnancy and birth control pills. Pulmonary hypertension can cause serious complications to both mom and her baby. Birth control pills can increase the risk of blood clots. Talk to your doctor about alternative forms of birth control.
• Don't travel to or live at high altitudes. High altitudes can worsen the symptoms of pulmonary hypertension. If you live at an altitude of 8,000 feet (2,438 meters) or higher, your doctor might recommend that you move to a lower altitude.
• Avoid situations that can excessively lower blood pressure. These include sitting in a hot tub or sauna or taking long hot baths or showers. Such activities lower blood pressure and can cause fainting or even death. Also avoid activities that cause prolonged straining, such as lifting heavy objects or weights.
• Eat healthy and manage your weight. Eat a healthy diet rich in whole grains, fruits and vegetables, lean meats, and low-fat dairy products. Avoid saturated fat, trans fat and cholesterol. Your doctor may recommend limiting the amount of salt in your diet. Aim to maintain a healthy weight.
• Ask your doctor about medications. Take all your medications as prescribed. Ask your doctor about any other medications before taking them, as some can interfere with pulmonary hypertension treatments or make your symptoms worse.
• Get regular doctor checkups. Your doctor may recommend regular follow-up appointments. Let your doctor know if you have any questions about your condition or the medications you're taking, or if you have any symptoms or side effects from your medications. If pulmonary hypertension affects your quality of life, ask your doctor about options that could help. Your doctor may work with another specialist to determine and manage the best drug treatment for pulmonary hypertension.
• Get recommended vaccines. Your doctor may recommend getting Covid-19, influenza and pneumonia vaccines, as these conditions can cause serious issues for people with pulmonary hypertension.
• Get support. If you're feeling stressed or worried due to your condition, get support from family or friends. Or consider joining a support group with others who have pulmonary hypertension.

If you think you might have pulmonary hypertension or are worried about your pulmonary hypertension risk, make an appointment with your family doctor.

While shortness of breath is one of the first symptoms of pulmonary hypertension, the symptom is also common with many other conditions, such as asthma.

Because appointments can be brief, and because there's often a lot to discuss, it's a good idea to be prepared for your appointment. Here's some information to help you get ready for your appointment, and what to expect from your doctor.

What you can do

• Be aware of any pre-appointment restrictions. At the time you make the appointment, be sure to ask if there's anything you need to do in advance, such as fill out forms or restrict your diet. For some imaging tests, for example, you might need to fast for a period of time beforehand.
• Write down any symptoms you're having, including any that might seem unrelated to pulmonary hypertension. Try to remember when they began. Be specific, such as days, weeks and months, and avoid vague terms such as "some time ago."
• Write down key personal information, including any family history of pulmonary hypertension, lung disease, heart disease, stroke, high blood pressure or diabetes, and any major stresses or recent life changes.
• Make a list of all medications, as well as any vitamins or supplements that you're taking. Also, be sure to tell your doctor if you've recently stopped taking any medications.
• Take a family member or friend along, if possible. Sometimes it can be difficult to remember all the information provided to you during an appointment. Someone who comes with you might remember something that you missed or forgot.
• Be prepared to discuss your diet and exercise habits. If you don't already follow a diet or exercise routine, talk to your doctor about any challenges you might face in getting started.
• Write down questions to ask your doctor.

Your time with your doctor is limited, so preparing a list of questions will help you make the most of your time together. List your questions from most important to least important in case time runs out. For pulmonary hypertension, some basic questions to ask your doctor include:

• What is likely causing my symptoms or condition?
• What are other possible causes for my symptoms or condition?
• What kinds of tests will I need?
• What's the most appropriate treatment?
• What's an appropriate level of physical activity?
• How often should I be screened for changes in my condition?
• What are the alternatives to the primary approach that you're suggesting?
• I have other health conditions. How can I best manage them together?
• Are there any restrictions that I need to follow?
• Should I see a specialist?
• Is there a generic alternative to the medicine you're prescribing?
• Are there any brochures or other printed material that I can take home with me? What websites do you recommend?

In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask other questions during your appointment.

What to expect from your doctor

Your doctor is likely to ask you a number of questions. Being ready to answer them might reserve time to go over any points you want to spend more time on. Your doctor might ask:

• When did you first begin having symptoms?
• Have your symptoms been continuous or occasional?
• How severe are your symptoms?
• What, if anything, seems to improve your symptoms?
• What, if anything, seems to worsen your symptoms?

What you can do in the meantime

It's never too early to make healthy lifestyle changes, such as quitting smoking, cutting down on salt and eating a healthy diet. These changes may help prevent pulmonary hypertension from getting worse.