Inflammation caused by lupus may affect the lungs in many ways, and can involve the membrane lining of the lungs, the lungs themselves, the blood vessels within the lungs, and the diaphragm.
The most common way that lupus can affect your lungs is through inflammation of the pleura, the lining that covers the outside of the lungs. The symptom of pleuritis that you may experience is severe, often sharp, stabbing pain in a specific area or areas of your chest. The pain, which is called pleurisy, is made worse when you take a deep breath, cough, sneeze, or laugh. You may also experience shortness of breath. Sometimes an abnormal amount of fluid will build up in the space between your lungs and your chest wall; when it leaks out it is called a pleural effusion. Pain from pleurisy, with or without effusions, is found in 40 to 60 percent of people with lupus.
The term for inflammation within the lung tissue is pneumonitis. The symptoms of pneumonitis that you may experience are fever, chest pain, shortness of breath, and cough. An infection caused by bacteria, virus, or fungi is the most common cause of pneumonitis.
Chronic diffuse interstitial lung disease
When inflammation in the lungs is chronic, it can cause scarring. This scar tissue can prevent oxygen from moving easily from your lungs into your blood and may cause diffuse (widespread) interstitial lung disease. The symptoms that you may experience include a chronic dry cough, chest pain, and difficulty breathing during physical activity.
Blood clots that block the arteries leading to the lungs are called pulmonary emboli. These blood clots will cause chest pain and shortness of breath, but can also lead to a decrease in oxygen flow in your lungs. You are at increased risk for pulmonary emboli if you have antiphospholipid antibodies, vascular damage, and/or an inactive lifestyle.