How is sarcoidosis diagnosed?

Sarcoidosis can be difficult to diagnose. It shares symptoms with lots of other diseases and you may not have any obvious symptoms. This means it can take a while to get a diagnosis.

You might need to have a few different tests, depending on which parts of your body are affected. This is because there is no single specific test to diagnose sarcoidosis.

Pulmonary sarcoidosis

If it looks like sarcoidosis is affecting your lungs, you’ll probably have lung function tests and a chest X-ray or CT scan.

A CT scan uses a special X-ray machine to make a detailed image of the inside of your body. In some cases, this may be enough to find out if you have sarcoidosis, but doctors will often need more information.

In some cases, the doctor may want to examine the inside of your lungs more closely by doing a bronchoscopy. This is done using a bronchoscope – a thin, flexible tube with a light and a very small camera at one end. The tube is passed through your nose or mouth, down your windpipe and into your lungs.

The procedure isn’t painful, but it can make you cough. It’s often done under sedation with a local anaesthetic. Your doctor will be able to give you more details when they discuss the test with you.

During the procedure, your doctor may take a sample of tissue from your lungs. This can be examined under a microscope to see if there are any granulomas. This is called a biopsy.

Many centres now prefer to do this using an EBUS-TBNA procedure. The doctor uses a special kind of bronchoscope with ultrasound at the tip to see inside your lungs and take a tissue sample. This procedure takes slightly longer than a standard bronchoscopy. But it’s more likely to give a clear diagnosis than a standard bronchoscopy.

Sarcoidosis in other parts of your body

You may have blood tests, urine tests or a biopsy of the affected area. You may also have an electrocardiogram, sometimes called an ECG, which is a simple test that records the rhythm of your heart.

If you’re diagnosed with sarcoidosis in one part of your body, other parts of your body may also be affected. Further tests will help to show how different parts of your body are affected.

Next: how is sarcoidosis treated? >