Pulmonary fibrosis is a condition that causes lung scarring and stiffness. This keeps the body from getting enough oxygen. Increased scarring makes breathing difficult and affects the heart.
The causes of pulmonary fibrosis can be divided into four categories: autoimmune diseases, genetics, chemical exposure, and unknown causes.
Autoimmune diseases cause the body’s immune system to attack itself. Conditions that can result in pulmonary fibrosis include:
- Churg-Strauss syndrome
- lupus erythematosus (lupus)
- rheumatoid arthritis (RA)
Lupus, RA, and scleroderma are most commonly associated with pulmonary fibrosis (Pulmonary Fibrosis Foundation, 2013).
Exposure to altering agents can cause pulmonary fibrosis. Cigarette smoke contains many chemicals that can damage the lungs. Other substances that damage the lungs include asbestos fibers, gases, grain dust, radiation, and silica dust.
Some medications can be associated with pulmonary fibrosis. Patients with a family history of pulmonary fibrosis should speak with their doctors before accepting certain medications. Some medications that can damage the lungs include:
- cardiac drugs, such as amiodarone or propranolol
- chemotherapy drugs, such as cyclophosphamide
- select antibiotics, such as nitrofurantoin or sulfasalazine
Some causes of pulmonary fibrosis are unknown. When this is the case, the condition is called idiopathic pulmonary fibrosis (IPF). This diagnosis represents a significant portion of pulmonary fibrosis cases (National Heart, Lung and Blood Institute, 2011).
For the most part, pulmonary fibrosis does not have a known cause.
People with a greater likelihood of being diagnosed with pulmonary fibrosis:
- are between the ages of 40 and 70
- are male (Pulmonary Fibrosis Foundation, 2013)
- have a history of smoking
- have undergone cancer treatments, particularly chest radiation
- work in an occupation associated with increased risk, such as mining, farming, or construction
A genetic counselor can evaluate your health risks if you have a pulmonary fibrosis family history.
A person can have pulmonary fibrosis for some time without any symptoms. Shortness of breath is typically the first symptom. Because the condition generally affects older people, symptoms are usually attributed to age or lack of exercise.
Pulmonary fibrosis affects the lungs and breathing. Symptoms include:
- abnormal lung sounds, such as crackling
- aching joints and muscles
- a chronic, dry, and hacking cough
- clubbing, where fingernails appear curved
- frequent shortness of breath
- sudden weight loss
Symptoms may seem minor at first and progress over time. But symptoms can vary from person to person. Some patients become ill very quickly.
More than 200 types of lung disease exist. Pulmonary fibrosis is one of them. Because there are so many, doctors often have trouble identifying IPF over other conditions. As many as 50 percent of patients with pulmonary fibrosis may have been misdiagnosed at one time (Pulmonary Fibrosis Foundation, 2013).
A doctor will use a variety of diagnostic tools to diagnose pulmonary fibrosis. These include imaging scans, such as a chest X-ray, echocardiogram, and computed tomography (CT) scan.
Other tests measure how well the lungs are working. A spirometry can test lung capacity. A treadmill stress test shows how lungs respond to physical activity.
The most definitive way to diagnose pulmonary fibrosis is by taking a tissue sample. This is an invasive procedure. A tissue sample can be taken with a bronchoscopy, in which a small tube is passed through the mouth to the lungs.
If a larger sample is needed, a surgical biopsy is performed. A physician makes several small incisions to access the lung tissue. A physician reading the biopsy can decide how far the condition has progressed.
There is no cure for pulmonary fibrosis. Scarring cannot be reversed. Treatments aim to slow the disease and improve breathing. The best treatments and medications vary by individual patient.
Medications used to treat pulmonary fibrosis have different aims. Examples include:
- Prednisone is a corticosteroid that lowers the immune system and reduces inflammation.
- Methotrexate and cyclosporine suppress the immune system.
- N-acetylcysteine is an antioxidant often used with other drugs to slow the disease’s progression.
- Pirfenidone reduces inflammation and scarring; this medication is pending U.S. approval as of April 2013 (Pulmonary Fibrosis Foundation, 2013).
Oxygen therapy can make breathing and sleeping easier. This therapy involves wearing a plastic tube in each nostril. The tubes receive oxygen from a tank. Pulmonary rehabilitation is another option. It focuses on techniques that make breathing easier.
Younger patients who do not respond to these treatments might need a lung transplant.
Smokers with pulmonary fibrosis should take steps to quit smoking. This slows the disease’s progress and eases breathing. Patients should also avoid secondhand smoke.
People with pulmonary fibrosis often lose weight because eating affects breathing. A nutritionist or dietitian can recommend high-calorie foods that are easy to eat.
Lifestyle changes, including exercise, improve lung function and strengthen the heart. Stronger muscles mean a patient becomes tired less easily and has more energy. Getting lots of rest and trying to stay relaxed whenever possible can improve breathing.
The rate at which pulmonary fibrosis scars the lungs varies from person to person. Scarring cannot be reversed. A doctor can try different treatments to reduce the rate at which pulmonary fibrosis progresses. People diagnosed with pulmonary fibrosis typically live about three to five years (American Lung Association, 2013).
The condition causes a number of complications, including lung cancer. It can also cause respiratory failure. This is when the lungs no longer work properly and cannot get oxygen to the blood.
Causes of IPF are unknown, so prevention is not possible. The best way to prevent pulmonary fibrosis is to avoid smoking and secondhand smoke and thus limit exposure to harmful chemicals. Factory workers should wear proper breathing devices to limit exposure.
Written by: Rachel Nall
Medically reviewed by George Krucik, MD, MBA