Interstitial lung disease (ILD) is a group of lung disorders that affect the interstitium of the lungs. Interstitium refers to those tissues that surround the alveoli or tiny air sacs of the lungs. This disease causes scarring and inflammation of these tissues, thus disturbing the overall functioning of the lungs. Usually, it affects all the tissues. This hampers the breathing ability and oxygen exchange in the bloodstream.
Scarring of the lung tissues is caused due to injury and abnormal healing responses of the body. Various factors may trigger the inflammation of the interstitium. Some of the factors include prolonged exposure to environmental pollutants, allergies, infections by microorganisms bacteria, virus and fungi, exposure to radiation therapy, side effects of strong medications, and other underlying diseases.
Many times, this disease is caused due to unknown reasons, which is a type of idiopathic pulmonary fibrosis. People who smoke or those having a family history of interstitial lung disease are more susceptible to the idiopathic type. One of the most common types of interstitial lung disease is usual interstitial pneumonitis that affects only a portion of the lung tissues. In spite of the name, it is not caused due to infection. Women who are above 50 years are at a higher risk of developing interstitial pneumonitis.
The most common symptoms of interstitial lung disease are difficulty in breathing, shortness of breath or breathlessness during physical activities, and prolonged dry cough. Though these symptoms are similar to many health conditions like aging process, obesity, and upper respiratory infection, patients tend to ignore the symptoms. Hence, early diagnosis is difficult.
As the damage of the lung tissue progresses, the symptoms may worsen. In such a condition, patients may feel breathlessness without exertion, during rest, or while doing routine activities. Other less noticeable signs include wheezing, chest pain, and finger clubbing. In most cases, it develops gradually. However, at times, people suffer from sudden onsets of the symptoms.
Interstitial lung disease is diagnosed based on the symptoms and physical examination of the patient. For confirmation, the pulmonologist may conduct chest X-rays, lung function test, blood test, and computed tomography (CT) of the thorax. In case the results of these laboratory tests are unclear, the pulmonologist may conduct a biopsy of the lung tissues in order to rule out other medical problems.
If scarring of the interstitium occurs, it cannot be cured. Hence, once a patient develops this disease, he/she cannot regain the normal metabolic activity of the lungs. The main objective for treatment is to manage the symptoms and slow down the damage. Treatment usually differs from one patient to another, and is based on the particular symptoms manifested by the patient. Based on the symptoms, the pulmonologist may prescribe corticosteroids, oxygen supplementation, and other vaccination. In severe cases, the pulmonologist may conduct lung transplantation.