Autoimmune diseases have the capacity to either directly or indirectly affect the lungs. People with an autoimmune disease should be cognizant of symptoms, such as chest pain or shortness of breath, which may require a pulmonary function test (PFT) for an accurate and specific diagnosis.


The most basic way autoimmune diseases can affect the lungs is causing inflammation. Pleurisy occurs when the membrane that surrounds the lungs is inflamed. This membrane is normally smooth and helps reduce friction so the lungs can glide smoothly against other organs in the chest cavity. When the membrane becomes inflamed, the lungs rub against the membrane. Not only is the condition painful, especially when taking a deep breath, but medical professionals will typically hear friction sounds when listening to the patient's breathing. Episodes of pleurisy caused by autoimmune diseases are often treated with steroids and pain-relievers to reduce symptoms. Additionally, better control of the underlying disease can reduce future episodes of pleurisy.

Interstitial Lung Disease

Interstitial lung disease (ILD) includes several disorders that cause the formation of scar tissue within the lungs. People with autoimmune diseases are considered to have a higher risk of developing ILD. When scar tissue forms in the lungs, it inhibits normal breathing functions. If ILD is suspected, a PFT may reveal decreased diffusing capacity, which means there is a decreased capacity for normal gas exchange. When gas exchange is decreased, this leads to shortness of breath and problems when adequate carbon dioxide cannot be exhaled.

One type of ILD is sarcoidosis which causes inflamed tissue in the lungs, eyes, and skin. Since sarcoidosis is a type of autoimmune disease, it may occur with periods of flare-ups and remission. In severe cases, sarcoidosis may be progressive, with lung damage becoming worse over time. A combination of disease-modifying anti-rheumatic drugs (DMARDs) and steroids may be used to suppress inflammation and gain control over the disease.


Ankylosing spondylitis (AS) is a form of inflammatory arthritis that affects the central skeleton, which includes the ribs, spine, and pelvis. Over time the bones in these areas become fused, which reduces or eliminates movement. When AS affects the ribs and the ribs become fused, it prevents the ribs from expanding normally when a person breathes. In this situation, the person cannot take a deep breath because the ribs do not allow full expansion of the lungs. A PFT will likely show results consistent with restrictive lung disease, such as reduced total lung capacity. The best course of treatment for AS is early diagnosis and intervention with biologics. When the disease is caught and treated early, there is less risk of joint fusion.

There are many ways autoimmune diseases can contribute to lung problems. Regular monitoring of lung involvement and testing of lung function can prevent or reduce problems before they cause irreversible damage to the lungs.