Quick answer. Sarcoidosis is an inflammatory condition in which small clusters of inflammatory cells (granulomas) form in the body, most often in the lungs and lymph nodes. Many people improve on their own without treatment, while others need medication such as steroids to settle the inflammation.
Sarcoidosis is an inflammatory condition in which the immune system forms tiny lumps of inflammation called granulomas in one or more parts of the body. The lungs and the lymph nodes in the chest are affected most often, but sarcoidosis can also involve the skin, eyes, joints, and other organs. Symptoms range from none at all to a persistent cough, breathlessness and fatigue.
In Singapore, sarcoidosis is seen by respiratory physicians and can be tricky to diagnose because its symptoms overlap with many other conditions, including infections. The encouraging news is that in many people sarcoidosis is mild and settles on its own without any treatment. When it is more active or affects important organs, effective medicines are available to control the inflammation. This guide explains what to look for and when to seek specialist care.
At a glance
| Area affected | Typical features | Usual approach |
|---|---|---|
| Lungs and chest lymph nodes | Dry cough, breathlessness, chest discomfort | Monitor if mild; medication if more active |
| General / whole body | Fatigue, fever, weight loss, night sweats | Assess cause; treat if symptoms troublesome |
| Skin | Bumps, patches, tender red lumps on the shins | Often settles; treatment if persistent |
| Eyes | Redness, pain, blurred vision | Prompt eye review to protect sight |
| Heart or nervous system | Palpitations, faints, neurological symptoms | Urgent specialist assessment and treatment |
What is sarcoidosis?
Sarcoidosis is a condition in which the immune system overreacts and forms small clusters of inflammatory cells called granulomas. These granulomas can collect in different organs, but the lungs and the lymph nodes inside the chest are involved in the great majority of cases. The granulomas can interfere with how the affected organ works, which is what produces symptoms.
It most commonly appears in adults, often between the twenties and forties. The course varies widely: some people have a single mild episode that resolves by itself within a couple of years, while others have a longer-term condition that needs ongoing care. Because it can affect several organs and mimic other illnesses, sarcoidosis sometimes takes time and several tests to diagnose, and respiratory physicians in Singapore often coordinate the assessment.
Symptoms & signs
Some people with sarcoidosis have no symptoms and it is found by chance on a chest X-ray. When symptoms occur, they depend on which organs are involved and may include:
- A persistent dry cough
- Breathlessness, especially on exertion
- Chest discomfort
- Marked tiredness and a general feeling of being unwell
- Fever, night sweats or unintended weight loss
- Skin changes – bumps, patches, or tender red lumps on the shins
- Red, painful or blurred eyes
- Swollen lymph glands and aching joints
Because these features are shared with many other conditions, it is the overall pattern and test results that point to sarcoidosis rather than any single symptom.
Causes & risk factors
The exact cause of sarcoidosis is not known. It is thought to result from the immune system reacting to a trigger – possibly an environmental or infectious one – in someone who is genetically susceptible, leading to the formation of granulomas. It is not an infection you can catch and it is not a cancer.
Factors that may be associated include:
- Age – most often diagnosed in adults aged roughly 20 to 40
- Family history – having a close relative with sarcoidosis
- Immune and genetic factors – that make some people more prone to the inflammatory response
It is important to understand that nothing the person did caused it, and it cannot be passed from person to person.
How it's diagnosed
Diagnosing sarcoidosis can be complex because no single test confirms it, and other conditions (including tuberculosis and lymphoma) must be excluded. A respiratory physician may use a combination of:
- Chest X-ray or CT scan – to look for enlarged chest lymph nodes or changes in the lungs
- Blood tests – to assess inflammation, organ function and calcium levels, and to help exclude other causes
- Lung function tests – to measure how well the lungs are working
- Biopsy – taking a small tissue sample (often from a chest lymph node) to confirm the typical granulomas; this is frequently the key step
- Eye, heart and other checks – if those organs may be involved
Putting these results together allows the specialist to make the diagnosis and judge how active the condition is.
Treatment options
Many people with sarcoidosis do not need any treatment, because the condition is mild and often improves on its own. When treatment is required, the aim is to calm the inflammation and protect the affected organs:
- Watchful monitoring – for mild disease, with regular reviews and scans to make sure it is settling rather than progressing
- Corticosteroids (steroids) – the main treatment when the condition is more active or affecting important organs such as the lungs, eyes, heart or nervous system
- Other immune-modulating medicines – used in some cases, often to allow lower steroid doses over the longer term
- Supportive care – such as treatment for cough, and managing fatigue
The plan is tailored to how active the disease is and which organs are involved. This guide does not quote prices, as treatment varies widely by individual.
When to see a doctor & which specialist
See a doctor if you have a persistent cough, ongoing breathlessness, unexplained fatigue, fever or weight loss, or skin or eye changes that do not settle – especially if these last for several weeks. Early assessment helps reach a diagnosis and identify whether any organs need protecting.
Seek urgent care – call 995 or go to A&E – if you develop severe breathlessness, chest pain, fainting, palpitations, or sudden visual loss. Although uncommon, sarcoidosis can affect the heart, eyes or nervous system, and these presentations need immediate attention. New or severe eye redness and pain also warrant prompt review to protect your sight.
The specialist who usually leads the assessment and treatment of sarcoidosis, particularly when the lungs are involved, is a respiratory physician (lung specialist). You can find one through our directory of respiratory physicians in Singapore. Care is sometimes shared with other specialists depending on which organs are affected.
Related guides
- Best Respiratory & Lung Clinics in Singapore — our editorial shortlist
- Keratoconus
- Ptosis (droopy eyelid)
- Mitral valve prolapse
- Pulmonary fibrosis
- Essential tremor
Sources
- NHS – Sarcoidosis
- Mayo Clinic – Sarcoidosis
- SingHealth – Conditions and treatments
- HealthHub Singapore
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