Pulmonary fibrosis is scarring in the lungs.
Pulmonary fibrosis develops when the alveoli, tiny air sacs that transfer oxygen to the blood, become damaged and inflamed. The body tries to heal the damage with scars, but these scars collapse the alveoli and make the lungs less elastic. If the cycle of inflammation and scarring continues, the lungs become increasingly unable to deliver oxygen to the blood. Changes in the lungs can also increase the blood pressure in the pulmonary artery.
Pulmonary fibrosis can result from many different lung diseases including sarcoidosis, drug reactions, autoimmune diseases, environmental allergies such as Farmer's lung, and exposure to toxic dusts and gases.
Pulmonary fibrosis that develops without a known cause is called idiopathic pulmonary fibrosis. This disease is equally common in men and women. It is usually diagnosed between the ages of 40 and 60.
Causes and symptoms
The causes and risk factors vary with the underlying disease. They may include genetics, environmental factors, and infections.
The first symptom of pulmonary fibrosis is usually shortness of breath—at first, during exercise, but later also while resting. Patients may also have a dry cough,a rapid heartbeat, or enlargement of the fingertips and ends of the toes. Some people feel tired or have a fever, weight loss, muscle or joint pains. In late stages of the disease, the lack of oxygen in the blood can give the skin and mucus membranes a blue tinge known as cyanosis.
Pulmonary fibrosis is often referred to a lung specialist. Several tests are usually needed to diagnose this disease and determine its cause. They include a physical examination, detailed history of the symptoms, chest x rays, lung function tests, and blood tests, including a measurement of the amount of oxygen in the blood. Computed tomography (CT scan) may give a more detailed picture of the lungs. Bronchoscopy may be done to examine the air passages and analyze the cells found deep in the lungs.
Lung biopsies are necessary to diagnose some diseases. Lung biopsies can be done through a needle inserted into the chest through the skin, during bronchoscopy, or as a surgical procedure under general anesthesia.