Sarcoidosis is a widespread immunity disorder, which can present itself in numerous different ways, but most primarily as a pulmonary disorder. In this literature review, the current state of scientific knowledge on the symptoms, pathophysiology, diagnostics, and treatment of the disorder is laid out. A brief historical introduction to sarcoidosis is also provided. It is found that sarcoidosis has a highly variable set of symptoms, which include patches on the skin and pulmonary dysfunction. The main mechanics of this disorder seem to surround T-cell and macrophage hyperactivity, resulting in the formation of granulomas and, if expressed in the lungs, pulmonary fibrosis. Diagnostic methods include biopsy, imaging, and biomarker analysis. Currently, treatment rests mostly on corticosteroids, though other medications can be of use, depending on the type of manifestation. The prognosis of the disorder is found to be varied: In most cases it will disappear spontaneously, but overall the mortality ranges from 1 to 10% of all cases. Definite, specific medication is not within reach yet, though with further research this might change.