In order for a sarcoidosis diagnosis to be made, all other diseases which could be causing the symptoms a patient is experiencing must be ruled out first. There are numerous other issues, including infection, exposure to toxic materials, and cancer that can cause similar problems, and a doctor will follow a process of elimination before determining if a person has sarcoidosis. Normally, he or she will start with the patient's medical history and a physical examination, and then move on to diagnostic tests like X-rays and CT scans, breathing tests, and biopsies to confirm.
There are many issues that can present with symptoms like cough and shortness of breath, swollen lymph nodes, and fatigue; these need to be ruled out prior to making a sarcoidosis diagnosis. Diseases like tuberculosis, rheumatic fever, or fungal infections of the lungs can all appear similar to sarcoidosis. Exposure to certain materials can cause issues like berylliosis or hypersensitivity pneumonitis, which have similar symptoms to granulomas in the lungs. Lung cancer can also mimic sarcoidosis. All of these issues and more must be eliminated as possible culprits.
In order to exclude all other problems and make a sarcoidosis diagnosis, a doctor must go through several steps to examine the patient. The first step is to take the patient's medical history, which can help him or her determine if the person has risk factors for other issues and if there are any factors that would point toward sarcoidosis. After that, a physical examination will normally be done to look for any symptoms of the disease, as well as signs that could indicate a different problem. Once these are complete, if no other issue seems likely, the doctor will move on to more detailed diagnostic tests to try and verify that sarcoidosis is the problem.
Several different diagnostic tests may be used for a sarcoidosis diagnosis. Chest X-rays are often done first to look for shadows in the lungs indicative of inflammation and granulomas, as well as swollen lymph glands. If the doctor needs a more detailed view, he or she may use a CT scan as well. Pulmonary function tests may be used to measure the patient's lung function and see if his or her breathing capacity has been reduced. It may be necessary to take a lung biopsy to see if granuloma tissue is present; this is typically accomplished through a bronchoscopy, where a tube is run down the trachea to the lungs and used to extract a tissue sample.
