Before we discuss what the types of interstitial lung disease are, let us have a look at what an interstitium is. The interstitium of the lung is the tissue and space that surrounds the air sacs of the lungs. This is a very thin, lacy network that is seen all over the lungs. This network gives the much-needed support to the alveoli (the air sacs).
The blood vessels running through the interstitium facilitate the exchange of gases between the blood and the air in the lungs.
What Are The Types of Interstitial Lung Disease?
The interstitial lung disease is usually classified according to its causes. This makes a long list of the types of the interstitial lung disease. To make it easily understandable, below are some of the types of interstitial lung diseases. All types of interstitial lung disease result into thickening or scarring of the interstitium. This thickening can also happen due to edema (extra fluid collection) and inflammation.
The types of interstitial lung disease are-
Idiopathic Pulmonary Fibrosis– it is a lung disease, caused by thickening and scarring of the lung tissue. When the root cause of pulmonary fibrosis is not known, it is known as idiopathic pulmonary fibrosis. This condition usually happens due to the injuries or factors that cannot be identified.
Interstitial Pneumonia– the interstitium of the lung may get affected due to viruses, bacteria or fungi. This may cause the thickening or scarring of the interstitium.
Hypersensitivity Pneumonitis- this is caused by the inhalation of mold, dust or any such type of irritants.
Nonspecific Interstitial Pneumonitis- this is associated with autoimmune conditions like rheumatoid arthritis.
Acute Interstitial Pneumonitis- this affects the interstitium suddenly and very severely. Life support is almost always needed.
Desquamative Interstitial Pneumonitis- this is partially caused by smoking.
Cryptogenic Organizing Pneumonia- this condition is pneumonia-like, but there is no infection present. It is also called bronchiolitis obliterans with organizing pneumonia.
Sarcoidosis– here, there are swollen lymph nodes, and sometimes an involvement of eye, heart, skin or nerve.
Asbestosis– this, as the name suggests is caused by over exposure to asbestos.
When an injury happens, our body generates tissue to repair the damage caused by the injury. Usually, the body generates just the right amount of tissue needed to repair the damage. But sometimes, this repair process loses its track and far too much tissue is generated than is actually necessary to repair the damage.
This is what exactly happens in the interstitial lung disease. This happens when there is an injury caused to the lungs and the body produces too much tissue and this result in the scarring and thickening of the tissue surrounding the air sacs (interstitium). This happens due to an abnormal healing process. As a result, it makes the passage of oxygen into the bloodstream a lot more difficult.
Interstitial lung disease (ILD) is a term used to separate these diseases from obstructive airway diseases. ILD is not one particular disease, but a category of diseases that includes many lung related conditions.
Diagnosis of Interstitial Lung Disease
The diagnosis of the interstitial lung disease needs imaging tests. The interstitium is a very fine, lacy network and cannot be seen in x-rays normally. When it is thickened or scarred like in ILD, it can be seen in the x-rays as fine lines. CT scan can usually reveal an interstitial lung disease. Sometimes, a high-resolution CT scan can be carried out. Pulmonary function test can be carried out, which reveals reduced total lung capacity. Once it is established that a person is suffering from interstitial lung disease, a lung biopsy is needed, as it is the only way most of the times to ascertain which type of interstitial lung disease has affected the lung.
Interstitial lung diseases vary from person to person and the prognosis largely depends on the causative factor and how far it has progressed to. Some ILDs worsen quickly, while the others progress slowly. Some can prove to be fatal.