Question: What is (are) Sarcoidosis ?
Answer: Sarcoidosis is an inflammatory disease characterized by the development and growth of tiny lumps of cells called granulomas. If these tiny granulomas grow and clump together in an organ, they can affect how the organ works, leading to the symptoms of sarcoidosis. The granulomas can be found in almost any part of the body, but occur more commonly in the lungs, lymph nodes, eyes, skin, and liver. Although no one is sure what causes sarcoidosis, it is thought by most scientists to be a disorder of the immune system. The course of the disease varies from person to person. It often goes away on its own, but in some people symptoms of sarcoidosis may last a lifetime. For those who need treatment, anti-inflammatory medications and immunosuppressants can help.
Source: GARD

Question: What are the symptoms of Sarcoidosis ?
Answer: What are the signs and symptoms of Sarcoidosis? Many people who have sarcoidosis don't have symptoms. Others may feel like they are coming down with the flu or a respiratory infection. While almost any body part or system can be affected, the lungs are most commonly involved. If granulomas form in the lungs, symptoms may include shortness of breath (dyspnea), a cough that won't go away, and chest pain. Some people feel very tired, uneasy, or depressed. Night sweats and weight loss are also common. Sarcoidosis can also cause the following: Skin rashes, ulcers or discoloration Joint stiffness or pain Enlarged lymph nodes Enlarged liver or spleen Vision problems, eye dryness or irritation Headaches, seizures, or weakness on one side of the face Aches and pains in the muscles and bones Abnormal heart beats Kidney stones The Human Phenotype Ontology provides the following list of signs and symptoms for Sarcoidosis. If the information is available, the table below includes how often the symptom is seen in people with this condition. You can use the MedlinePlus Medical Dictionary to look up the definitions for these medical terms. Signs and Symptoms Approximate number of patients (when available) Hepatomegaly 7.5% Splenomegaly 7.5% Optic neuropathy 5% Abnormality of the mouth - Anorexia - Arthritis - Blurred vision - Bone cyst - Cough - Dyspnea - Elevated erythrocyte sedimentation rate - Enlarged lacrimal glands - Exaggerated cellular immune processes - Fever - Generalized lymphadenopathy - Glaucoma - Hypercalciuria - Increased antibody level in blood - Inflammation of the large intestine - Interstitial pulmonary disease - Iridocyclitis - Pancytopenia - Photophobia - Weight loss - The Human Phenotype Ontology (HPO) has collected information on how often a sign or symptom occurs in a condition. Much of this information comes from Orphanet, a European rare disease database. The frequency of a sign or symptom is usually listed as a rough estimate of the percentage of patients who have that feature. The frequency may also be listed as a fraction. The first number of the fraction is how many people had the symptom, and the second number is the total number of people who were examined in one study. For example, a frequency of 25/25 means that in a study of 25 people all patients were found to have that symptom. Because these frequencies are based on a specific study, the fractions may be different if another group of patients are examined. Sometimes, no information on frequency is available. In these cases, the sign or symptom may be rare or common.
Source: GARD

Question: What causes Sarcoidosis ?
Answer: What causes sarcoidosis? No one yet knows what causes sarcoidosis. It is thought by most scientists to be a disorder of the immune system, where the body's natural defense system malfunctions. Some physicians believe that sarcoidosis may result from a respiratory infection caused by a virus. Others suspect that exposure to toxins or allergens in the environment is to blame. It's also possible that some people have a genetic predisposition to developing sarcoidosis, which, when combined with an environmental trigger, produces the disease. Studies are ongoing to investigate the genetic and environmental components of this disease.
Source: GARD