Your immune system is supposed to protect you, but sometimes it can make mistakes. In autoimmune conditions, your immune system thinks your body’s healthy tissues are actually foreign invaders and launches a misguided attack. This misdirected immune response can cause inflammation and damage to organs and blood vessels — including those in the lungs. Over time, this damage can lead to pulmonary hypertension (PH).

This article will explain how certain autoimmune diseases can increase the risk of pulmonary hypertension. You’ll learn how PH affects your body, which diseases are most likely to cause it, and what symptoms to watch out for. Finally, it will cover how doctors diagnose and treat PH in people with high-risk autoimmune conditions.

How Do Autoimmune Diseases Cause Pulmonary Hypertension?

Autoimmune diseases cause the immune system to mistakenly attack the body’s own tissues, leading to inflammation and damage. When this damage affects the pulmonary arteries — the blood vessels that transport oxygen-poor blood from the heart to the lungs for oxygenation — they can become narrow, stiff, or scarred. This makes it harder for blood to pass through, leading to increased blood pressure in these arteries, leading to pulmonary hypertension.

The World Health Organization (WHO) classifies pulmonary hypertension into five groups based on their symptoms and causes. One type is pulmonary arterial hypertension (PAH). There are four main types of pulmonary arterial hypertension:

• Heritable pulmonary arterial hypertension (HPAH) — This type is passed down through families. People with a family history of PH have a higher risk because of genetic mutations (changes) that affect how blood vessels in the lungs work.
• Idiopathic pulmonary arterial hypertension (IPAH) — “Idiopathic” means the cause is unknown. This type happens without a clear reason and isn’t linked to other diseases.
• Associated pulmonary arterial hypertension (APAH): This form of PAH happens because of another condition, like scleroderma, lupus, or rheumatoid arthritis (RA), all of which are autoimmune diseases. Inflammation or scarring from one or more of these diseases can damage the arteries in the lungs.
• PAH from past or current drug use — Some substances — such as methamphetamine or certain weight-loss medications — can trigger PAH by damaging the blood vessels in the lungs.

All four types involve narrow or stiff arteries in the lungs that make it harder for blood to flow. This raises blood pressure and forces the heart to work harder. Common symptoms may include:

• Dyspnea (shortness of breath), especially during activity
• Fatigue (extreme tiredness that does not improve with rest)
• Chest pain or pressure
• Dizziness or fainting

Autoimmune Conditions Linked to Pulmonary Hypertension

Not all autoimmune diseases cause pulmonary hypertension. However, those that affect connective tissue — the body’s network of support structures, including skin, joints, and blood vessels — are more likely to increase PH risk. These connective tissue diseases can lead to inflammation, scarring, and blood vessel damage, which may contribute to high blood pressure in the lungs. Below are some of the main autoimmune diseases linked to PH.

1. Rheumatoid Arthritis

Rheumatoid arthritis mainly affects the joints, causing pain, swelling, and stiffness. However, it can also affect other body parts, including the lungs. Chronic (long-term) inflammation from rheumatoid arthritis can lead to scarring of lung tissues and narrowing of the blood vessels. This can make it harder for blood to flow through the pulmonary arteries, leading to increased blood pressure. About 21 percent to 28 percent of people with RA will develop PH as well.

2. Lupus

Lupus is a disease where the immune system attacks different parts of the body, including the skin, joints, and organs. The most common type is called systemic lupus erythematosus. Lupus can cause pleurisy (inflammation of the lung’s lining) and other tissues. As a result, the pulmonary arteries can become damaged, leading to high blood pressure in these vessels. Studies estimate that between 0.5 percent and 9 percent of people with lupus also develop PAH.

3. Sjögren’s Disease

Sjögren’s disease mainly affects moisture-producing glands, causing dry eyes and mouth. However, it can also impact the lungs, leading to lung tissue damage, low oxygen levels, and blood vessel narrowing — all of which can contribute to PH. Around 16 percent of people with Sjögren’s experience some lung problems, including interstitial lung disease and PH.

4. Systemic Sclerosis

Systemic sclerosis, or scleroderma, causes hardening of the skin and connective tissues. It can also lead to scarring in the lungs and thickening of the pulmonary arteries, increasing PH risk. Up to 40 percent of people with scleroderma develop PH. Regular screening with noninvasive measures such as pulmonary function tests are important. Early intervention can help manage symptoms and slow disease progression.

5. Mixed Connective Tissue Disease

Like other autoimmune diseases, mixed connective tissue disease (MCTD) happens when the immune system attacks its own cells by mistake. MCTD shares features of other autoimmune diseases, including lupus and scleroderma. Studies show that about 12.5 percent of people with MCTD develop PAH.

Diagnosing and Managing Pulmonary Hypertension

Diagnosing pulmonary hypertension in people with autoimmune diseases can be challenging because many symptoms — such as shortness of breath and fatigue — overlap with autoimmune conditions themselves. However, early detection is crucial, as untreated PH can become life-threatening.

Screening and Diagnosis

People with autoimmune diseases like scleroderma, lupus, or MCTD are at higher risk of PH and should be screened regularly. Diagnosis typically begins with a review of medical history and symptoms. If a doctor suspects PH, they may order several tests, including:

• Echocardiogram (heart ultrasound) — This is often the first test used to estimate blood pressure in the lungs and assess how well the heart is pumping.
• Right heart catheterization — If an echocardiogram suggests PH, this procedure may be done to confirm the diagnosis. It’s more invasive but provides the most accurate measurement of pressure in the pulmonary arteries.
• Pulmonary function tests — These measure lung capacity and airflow, helping to identify lung-related causes of PH.
• Chest CT scan — This imaging test checks for lung damage, scarring, or other conditions that might contribute to PH.

Treatment Options for PH in People With Autoimmune Disease

Treating PH in people with autoimmune disease focuses on two goals — lowering blood pressure in the lungs and managing the underlying condition. Because PH affects each person differently, treatment plans are customized based on the severity and type of PH, as well as the specific autoimmune disease involved.

Medications are often a key part of PH treatment. Drugs called pulmonary vasodilators help open narrowed blood vessels in the lungs, lowering the blood pressure and making it easier for blood to flow. These may include:

• Endothelin receptor antagonists
• Phosphodiesterase-5 inhibitors
• Prostacyclin-class medications
• Soluble guanylate cyclase stimulators

• Activin signaling inhibitors

Managing Autoimmune Disease To Improve PH

Because autoimmune diseases contribute to PH by causing inflammation and blood vessel damage, treating the underlying condition is essential. This is done with immunosuppressants, medications that calm the overactive immune system. They include corticosteroids as well as other immunosuppressants. When autoimmune disease is well controlled, PH symptoms may also improve.

Other types of supportive treatment include oxygen therapy, used when oxygen levels are low to help improve breathing and energy levels.

Lifestyle changes can make a big difference, too. Eating a healthy diet, exercising as recommended, and avoiding smoking can all improve your outlook and help you manage PH.

Early treatment can ease symptoms, slow disease progression, and improve your overall quality of life.

Importance of Early Diagnosis

Autoimmune disease can quietly damage the lungs and raise blood pressure without clear warning signs. Regular screening, early diagnosis, and proper treatment are critical. This is especially true for those with autoimmune disease or other high-risk conditions.

If you experience any new or worsening symptoms, such as shortness of breath, chest pain, or dizziness, talk to your healthcare team right away. With early intervention, people with PH and autoimmune diseases can manage their symptoms better and improve their overall health.

Talk With Others Who Understand

On myPHteam, the social network for people with pulmonary hypertension and their loved ones, more than 56,000 members come together to ask questions, give advice, and share their stories.

Do you have PH that was caused by an autoimmune condition? How do you manage both conditions? Share your experience in the comments below, start a conversation by posting on your Activities page, or connect with like-minded members in Groups.