Sarcoidosis is a disease that results from a specific type of inflammation of tissues of the body. It can appear in almost any body organ, but it starts most often in the lungs or lymph nodes. The cause of sarcoidosis is unknown. The disease can appear suddenly and disappear. Or it can develop gradually and go on to produce symptoms that come and go, sometimes for a lifetime.

As sarcoidosis progresses, microscopic lumps of a specific form of inflammation, called granulomas, appear in the affected tissues. In the majority of cases, these granulomas clear up, either with or without treatment. In the few cases where the granulomas do not heal and disappear, the tissues tend to remain inflamed and become scarred (fibrotic).
Types of Sarcoidosis
Sarcoidosis can affect almost any part of the body, and depending on where it occurs, patients can experience very different symptoms and require different treatment methods. Additionally, a patient may experience more than one type of sarcoidosis at once. Some of the common types are discussed here.
Pulmonary sarcoidosis
Pulmonary sarcoidosis refers to sarcoidosis affecting the lungs. This is the most common form since the majority of sarcoidosis patients experience some level of lung involvement.
Ocular sarcoidosis
Ocular sarcoidosis refers to sarcoidosis affecting the eyes or the surrounding structures. It occurs in about 50 percent of sarcoidosis patients. The symptoms can vary depending on which parts of the eye are affected, with the most common complication being uveitis.
Neurosarcoidosis
When granulomas develop in and around the nervous system, the disease is referred to as neurosarcoidosis. Depending on the nerves affected, it can have a wide variety of symptoms. Neurosarcoidosis most commonly affects hormone-producing regions of the brain, the hypothalamus, and the pituitary gland. This can disrupt many systems, such as menstrual cycles in female patients.
Neurosarcoidosis can also affect the p