How is sarcoidosis diagnosed?

Sarcoidosis can be difficult to diagnose. It shares symptoms with lots of other conditions 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 straightforward test to diagnose sarcoidosis.

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Diagnosing pulmonary sarcoidosis

If it looks like sarcoidosis is affecting your lungs, you’ll have lung function tests and a chest X-ray or CT scan. Lung function tests can be done at your GP surgery or at a hospital. X-rays and CT scans are done in hospitals. You will be given an appointment and your appointment letter will tell you anything you need to do to get ready.

Sometimes your doctor will also send you for a PET scan. In this scan, you are injected with a sugary substance which the scanner can detect to see how your cells are working.

In some cases, you may have a bronchoscopy to look inside your lungs. This is done using a thin, flexible tube with a light and a very small camera at one end (bronchoscope). The tube is passed through your nose or mouth, down your windpipe and into your lungs.

This is not painful, but it can make you cough. A local anaesthetic will be used to numb your throat, so you do not feel too much discomfort.

At the same time, your doctor may take some tissue from your lungs. This is looked at under a microscope to see if there are any granulomas. This is called a biopsy.

Many hospitals now prefer to look inside the lungs using an EBUS-TBNA procedure (endobronchial ultrasound-guided transbronchial needle aspirate). The doctor uses a special kind of bronchoscope with ultrasound at the tip to see inside your lungs and take some tissue. You will be given sedation that will make you feel drowsy, so you’ll have to stay at the hospital for a while to make sure you’ve recovered. An EBUS-TNA procedure is more likely to give a clear diagnosis than standard bronchoscopy.

Diagnosing sarcoidosis in other parts of your body

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 this.

You may have blood tests, pee (urine) tests or a biopsy of the affected area. You may also have an electrocardiogram (ECG), which is a simple test that records the rhythm of your heart. Depending on your condition, other types of tests may also be necessary.

Next: how is sarcoidosis treated?

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