Sarcoidosis of the lung is a rare disease caused by inflammation. It is characterized by the growth of tiny collections of inflammatory cells, called granulomas, in any part of the body, most commonly the lungs and lymph nodes. These granulomas can affect how the lungs work and cause small lumps of inflammatory cells in the lungs. If they dont heal, the lung tissue can remain inflamed and become scarred and stiff, leading to pulmonary fibrosis, which changes the structure of the lungs and can affect breathing. The cause of sarcoidosis is unknown, but experts think it results from the bodys immune system responding to an unknown substance. Some research suggests that infectious agents, chemicals, dust, or a potential abnormal reaction to the bodys own proteins could be responsible for the formation of granulomas in people who are genetically predisposed. The symptoms of sarcoidosis vary depending on which organs are affected by the disease as well as its severity. The most common symptoms of sarcoidosis include fatigue, swollen lymph nodes, fever, a feeling of discomfort or illness, weight loss, and depression. If sarcoidosis affects the lungs, respiratory symptoms such as persistent dry cough, wheezing, shortness of breath, and chest pain may occur. Sarcoidosis is usually diagnosed when other lung disorders are ruled out. Treatment is generally done to control symptoms and improve the function of organs affected by the disease. Steroid medicine, such as prednisone, may help reduce inflammation. It can be taken by mouth or inhaled. Other medicines, such as methotrexate, may be used in severe cases or if steroids don’t work.