There is no cure for the inflammatory disease sarcoidosis. Virtually any part of the body can be affected but most often the lungs and lymph nodes. Outcomes after diagnosis vary widely among sarcoidosis patients, with some experiencing resolving disease and others developing chronic disease and lung fibrosis. Cardiac sarcoidosis can lead to life threatening arrythmias and calcium metabolism disturbances can lead to renal impairment. Treatment with different forms of immunosuppressants are usually tried to dampen symptoms but are not effective in all patients. Furthermore, the disease usually flares up after cessation of treatment. The variability in diseae course and treatment response is thought, at least to some degree, to be explained by individual differences in genetics, immune cells and signaling pathways. But existing evidence is limited. In other inflammatory diseases the gut microbiome is of importance for disease course but its role in sarcoidosis has not been clarified. In this prospective project the investigators will study genes, inflammatory cells and signaling molecules in the lung, upper airways and blood, and to some extent microbes, also in faeces. Healthy volunteers will be included for comparative studies. Most samples will be taken during normal diagnostic work-up and follow-up of patients with/with suspected sarcoidosis. The findings will be correlated to disease course and effects of different treatments. By linking to national health data and demographic registries, comorbidities and environmental factors will be correlated to data. By this, the investigators hope to improve understanding of which genes, cells and signaling molecules that are of importance for resolving vs non-resolving disease and why some patients respond to a certain treatment and others don´t. The overall goal is to assess and predict sarcoidosis outcomes. We hypothesize that blood-based biomarkers including those taken during routine care as well as novel cell, signaling molecules and genetic markers, in combination with clinical characteristics can be used to predict outcomes, also treatment response, in sarcoidosis. The results can lead to tailored treatment and individual follow-up for each patient with sarcoidosis.