There are differences in the type of inflammation that help differentiate the diagnoses of these disorders. Sometimes CT scanning provides a more detailed picture that can help eliminate other possibilities. Infiltration refers to the abnormal presence of granulomas in the lung tissue. Depending on how severe and extensive the pulmonary infiltration is, it can cause various respiratory symptoms. Fibrosis tends to develop in areas where the infiltration lasts a long time or where it is especially dense.
Fibrosis causes the lungs to stiffen, making it difficult to breathe.
Unfortunately, fibrosis is irreversible. If extensive, it can cause severe dysfunction and, at its worse, can lead to heart failure. In the majority of patients, the inflammation and infiltration in the lungs eventually clears up. There is considerable difference among racial groups in the likelihood of the sarcoidosis clearing up without causing any permanent damage. The percentage of cases that resolve decreases as the stage increases.