Sarcoidosis is an inflammatory condition in which immune cells form small clusters called granulomas. It can affect almost any organ, but the lungs and lymph nodes in the chest are affected most often. Some people have few or no symptoms, while others develop persistent or serious organ involvement.
Symptoms
Symptoms depend on which organs are affected and may include:
- persistent dry cough, shortness of breath, wheezing or chest discomfort
- fatigue, fever or unexplained weight loss
- swollen lymph nodes
- painful or swollen joints
- skin rashes, tender bumps or other skin changes
- red or painful eyes, light sensitivity or blurred vision
- palpitations, an irregular heartbeat, dizziness or fainting
- headache, weakness, numbness, seizures or other neurological symptoms when the nervous system is affected
Sarcoidosis can be present without obvious symptoms and may sometimes be discovered on chest imaging performed for another reason.
What causes sarcoidosis?
The exact cause is not fully understood. Research suggests that environmental or infectious triggers may cause an abnormal immune response in genetically susceptible people. Sarcoidosis is not contagious.
Diagnosis
There is no single test that diagnoses every case of sarcoidosis. A healthcare professional considers symptoms, medical history, physical examination and test results while ruling out other conditions that can look similar.
Tests may include chest X-rays or CT imaging, lung function tests, blood and urine tests, an electrocardiogram, heart imaging and an eye examination. A biopsy of the lung, lymph node, skin or another affected tissue may be used to look for granulomas and support the diagnosis.
Treatment
Not everyone with sarcoidosis needs treatment. Mild disease may improve without medicine, but follow-up remains important because symptoms and organ involvement can change.
When treatment is needed, corticosteroids such as prednisone are commonly used to reduce inflammation. Other medicines that suppress or modify immune activity, including methotrexate and other specialist treatments, may be considered when corticosteroids are not suitable or do not control the disease. Treatment depends on which organs are affected and how severely they are affected.
People with significant lung disease may benefit from pulmonary rehabilitation or oxygen therapy. Serious heart, neurological, eye or other organ involvement requires specialist care.
Monitoring and everyday care
Regular follow-up may include lung function testing, imaging, blood tests, eye examinations or heart tests. Avoid smoking and unnecessary exposure to lung irritants. Physical activity can help maintain strength and wellbeing when appropriate for the individual.
Sarcoidosis can sometimes affect calcium and vitamin D metabolism. Discuss calcium or vitamin D supplements with a healthcare professional before taking them if you have sarcoidosis.
When to seek urgent medical help
Seek prompt medical assessment for new or worsening breathlessness, eye pain or vision changes, palpitations, dizziness, fainting, weakness, numbness or other significant new symptoms.
Use your local emergency medical service for severe breathing difficulty, sudden severe chest pain, loss of consciousness, a seizure, sudden major weakness or a sudden major change in vision.
Related topics
Sources
- National Heart, Lung, and Blood Institute: Sarcoidosis
- NHLBI: Sarcoidosis Diagnosis
- NHLBI: Sarcoidosis Treatment
- MedlinePlus: Sarcoidosis
Last reviewed: 4 September 2026. This page provides general health information and does not replace individual medical advice.