What is sarcoidosis?

"What is needed is guidance, explanation, information and understanding" (Patient, The Netherlands)

Sarcoidosis is a rare condition in which patches of red, swollen tissue (granulomas) form in various parts of the body.

Sarcoidosis affects many organs in the body, with the lungs the most commonly affected. However, it is considered to be a multisystemic condition, as it can affect the skin, eyes, heart, muscles, joints, bones, liver, kidneys and brain. Read more about how these organs can be affected.

Most people with sarcoidosis get better without specific treatment within 12-18 months and go on to lead normal lives. This is because the body's immune system can heal the condition over time.

Sometimes, for reasons that are not understood, the immune system does not heal the granulomas and scar tissue forms (fibrosis). This can result in damage to the affected body part that requires long-term treatment and monitoring.

There are treatments that can help to slow the disease and improve symptoms. However, no treatment is available to cure this condition.


"Finding doctors who know about sarcoidosis is difficult! Set up sarcoidosis centers!" (Patient, Germany)

Scientists do not currently know the cause of sarcoidosis, but there is research being carried out to try and answer this question.

What we do know is:

  • Sarcoidosis is not infectious (you cannot catch it and you cannot pass it to another person)
  • Sarcoidosis is not a form of cancer
  • Sarcoidosis does run in families, but there is only a 5-10% chance someone else in your family will have the condition.


"It can be difficult for patients, as we live in constant doubt about different signs and symptoms that occur, and do not know if they are related to the disease or not" (Patient, Spain)

Diagnosing sarcoidosis can be difficult. Symptoms are very varied and no single test gives a definite diagnosis for this condition.

Diagnostic tests

“It is important for someone with possible symptoms to see an organised team of doctors with a high-case number” (Patient, Germany)

It may take a long time for doctors to make a diagnosis as they must rule out other conditions that look like sarcoidosis, and no two people will present with the same combination of symptoms.

How does it progress?

“It would be nice if one doctor could understand and help to explain the effects of sarcoidosis, I am under so many different specialists that I don't always get the whole picture.” (Patient, UK)

Most people who are diagnosed with sarcoidosis get better without specific treatment and go on to lead normal lives, but sometimes with damage to affected organs. Around 1 in 4 people will have long-term chronic symptoms that require ongoing treatment.

Sarcoidosis in children

Sarcoidosis in children is extremely rare. The actual number of children with sarcoidosis is hard to assess due to the lack of an international systematic reporting system, but it has been estimated at approximately 0.4 to 1 per 100,000 children. Sarcoidosis has to be distinguished from Blau syndrome, which is another granulomatous condition that affectschildren.

Children of all ages can be affected by sarcoidosis, with the mean age at diagnosis being 11 to 13 years-old with equal numbers in both male and females. Only 3 studies have been published to date, two of them reporting a greater number of black children diagnosed with sarcoidosis in more than two thirds of cases.