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These could be hallmark symptoms of pulmonary arterial hypertension (PAH), a type of high blood pressure in your lungs. It's different from high blood pressure in the rest of your body.

Blood Vessels

PAH affects your pulmonary arteries.

Those are blood vessels that branch from the right side of your heart out to your lungs. They carry blood low in oxygen back to the lungs. This process acts as a kind of exchange: with breathing. Your lungs take carbon dioxide out of blood and put oxygen back in.

But when you have PAH, something changes or hurts the cells that line the arteries in your lungs. This makes the walls of those small blood vessels stiff, or narrow. Your heart works overtime to push blood through this tighter space, which can weaken it.

Scientists aren't exactly sure why these cell injuries happen in some people.

For example, PAH is more common in women between the ages of 30 to 60. Certain mutations, or gene changes, show up in some people with PAH. And some have a connective tissue disorder, like scleroderma. PAH is also linked to other health conditions, such as heart disease you're born with and liver disease.

People who use drugs like cocaine, methamphetamines, and some banned diet pills sometimes get PAH, too.

We may not know what kicks off the condition in any one person. But it's clear that with pulmonary hypertension the walls of your pulmonary arteries grow more than they should.

Heart and Lungs

The right side of your heart tries to keep up with the added stress.

It must get blood through the lungs and to the left side of your heart, which pumps blood to the rest of your body. Your lungs are usually a low-pressure system, so the elevated pressure in PAH has a huge impact on the heart.

This extra force strains your heart's lower right chamber, or ventricle. That's a big problem. The right side of your heart isn't as muscular and strong as the left. It can't handle this high-pressure burden for very long.

The heart tends to change shape as it adapts to this overload.

The left side of your heart is used to contract against a lot of pressure. But it can't hold as much oxygenated blood when it shrinks. This makes it even harder for your body to get enough oxygen, especially when you're moving.

As for your lungs, PAH can raise the odds of blood clots in your small pulmonary arteries. You can get bleeding in your lungs. This could cause you to cough up blood.

How to Live with PAH

How PAH Affects the Rest of Your Body

Weak blood flow from PAH or a weakened heart triggers a domino effect.

Here's some of what could happen:


This means you have low levels of oxygen in your blood. When that happens, your usual amount of physical activity may be harder. As a result, your skeletal muscles can weaken, including the ones that help you breathe. Your lips or skin might take on a blue tint (cyanosis).


This is when your veins swell with blood. It happens when the blood returning to your heart gets backed up. Fluid might build up. You may see swelling in your face, legs, ankles, and belly.

Tissue and organ damage.

Edema can tax other parts of your body, including your gut, eyes, and kidneys. Your spleen and liver can become swollen You might get a type of liver disease if this goes on for a long time.

Blood count problems.

Your platelet numbers might go down. Those are blood cells that help your blood clot. Your chances of this happening go up if your liver and spleen swell.

Poor sleep.

Your oxygen levels might dip even lower when you sleep. That's called nocturnal hypoxemia. It's common in people who have PAH. On top of that, sleep-disordered breathing problems, such as sleep apnea, can make it even harder to take in enough air.

Memory and attention problems.

Experts aren't sure why this happens to some people. They think it might have something to do with low levels of oxygen in the brain. More research is needed. The good news is PAH therapies seem to boost cognitive function.

What Happens if You Don't Treat PAH

There are ways to live longer and boost your quality of life, even if you can't cure PAH.

You might need a mix of medication, lifestyle changes, oxygen therapy, or other treatments.

If left untreated, this might happen within 5 years of your diagnosis.

As the right side of your heart starts to fail, you might get more shortness of breath, fatigue, and chest pain. This will be really obvious when you try to exercise. But you also might not have enough energy to do simple, daily things.

Some days you might be so out of breath you have to stay in bed. You might have more dizzy spells or pass out. If you fall, you can hurt yourself.

PAH is a complex disease. But your health care team can help you figure out a treatment plan.

It's best to work with someone who knows a lot about your condition. You may need to see an expert at a pulmonary hypertension care center. Ask your regular doctor for a referral.

Visit the Pulmonary Hypertension Association website for more information. They can help you find a specialist in your area.

Reviewed by Brunilda Nazario, MD, on October 30, 2023

Michael Duncan, MD, assistant professor of clinical medicine (pulmonary and critical care), Indiana University (IU) School of Medicine.

Carlos Mena-Hurtado, MD, director, Peripheral Vascular Disease Program; co-director, Vascular Medicine Outcomes Program, Yale Medicine; associate professor of medicine (cardiology), Yale School of Medicine.

National Organization for Rare Disorders (NORD): “Pulmonary Arterial Hypertension.”

American Heart Association: “Pulmonary Hypertension — High Blood Pressure in the Heart-to-Lung System,” “Types of Heart Failure.”

American Journal of Managed Care: “The Myth of the Stable Pulmonary Arterial Hypertension Patient.”

Cleveland Clinic: “Pulmonary Arteries.”

American Lung Association: “Learn About Pulmonary Arterial Hypertension,” “Treating and Managing Pulmonary Arterial Hypertension.”

Circulation Research: “Pulmonary Arterial Hypertension: The Clinical Syndrome.”

Circulation: “Systemic Consequences of Pulmonary Hypertension and Right-Sided Heart Failure.”

Cell Metabolism: “The Metabolic Basis of Pulmonary Arterial Hypertension.”

Frontiers in Physiology: “Left-Ventricular Energetics in Pulmonary Arterial Hypertension-Induced Right-Ventricular Hypertrophic Failure.”

Mayo Clinic: “Pulmonary Hypertension.”

Respiratory Research: “Cognitive, emotional, and quality of life outcomes in patients with pulmonary arterial hypertension.”

Advanced Emergency Nursing Journal: “Pulmonary Arterial Hypertension Emergency Complications and Evaluation.”

Diseases: “Pulmonary Arterial Hypertension: Pathophysiology and Treatment.”

Pulmonary Hypertension Association: “Treatments,” “Diet and Nutrition,” “Support Group May and Meeting Calendar,” “When Is It An Emergency?

National Heart, Lung, and Blood Institute: “Pulmonary Hypertension.”

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