Although rheumatoid arthritis primarily affects joints, it sometimes also causes lung disease. Occasionally, lung problems surface before the joint inflammation and pain of rheumatoid arthritis.

Men in their 50s and 60s who have more-active rheumatoid arthritis and a history of smoking are more likely to develop rheumatoid arthritis-related lung disease.

The lung problems most often linked to rheumatoid arthritis include:

• Scarring within the lungs. Scarring related to long-term inflammation (interstitial lung disease) may cause shortness of breath, a chronic dry cough, fatigue, weakness and loss of appetite.
• Lung nodules. Small lumps can form in the lungs (rheumatoid nodules), as well as in other parts of the body. Lung nodules usually cause no signs or symptoms, and they don't pose a risk of lung cancer. In some cases, however, a nodule can rupture and cause a collapsed lung.
• Pleural disease. The tissue surrounding the lungs, known as the pleura (PLOOR-uh), can become inflamed. Pleural inflammation is often accompanied by a buildup of fluid between two layers of the pleura (pleural effusion). Sometimes the fluid resolves on its own. A large pleural effusion, however, can cause shortness of breath. Pleural disease may also cause a fever and pain on breathing.
• Small airway obstruction. The walls of the lungs' small airways can become thickened because of chronic inflammation and infection (bronchiectasis) or inflamed or injured (bronchiolitis). This may cause mucus to build up in the lungs, as well as shortness of breath, a chronic dry cough, fatigue and weakness.

Contact your doctor promptly if you have rheumatoid arthritis and experience any unexplained breathing problems. Sometimes treatment is aimed at the rheumatoid arthritis. In other cases, treatment involves medication to suppress the immune system or a procedure to remove fluid surrounding the lungs.