Symptoms of pulmonary fibrosis vary from one patient to the next. Symptoms most commonly develop over time and progressively become worse. Some patients may notice symptoms that worsen very quickly, while others may notice less severe symptoms that progress over a much longer period of time. Symptoms also are at least partially dependent on the cause of the fibrosis.
The symptoms of pulmonary fibrosis include:
- Shortness of breath, particularly during exercise
- Dry, hacking cough
- Fast, shallow breathing
- Gradual unintended weight loss
- Aching joints and muscles
- Clubbing (widening and rounding of the tips of the fingers or toes)
Causes and Risk Factors
Pulmonary fibrosis is associated with many conditions, but in most cases, the cause is never found. When this is the case, the condition is known as idiopathic pulmonary fibrosis. There are several theories being researched as to what might trigger idiopathic pulmonary fibrosis, including viruses and exposure to tobacco smoke. There are also types of idiopathic pulmonary fibrosis that appear to be hereditary, so there is likely a genetic component to the disorder.
Causes known to be associated with pulmonary fibrosis:
- Occupational and environmental factors, including long-term exposure to silica dust, asbestos fibers, grain dust, bird and animal droppings.
- Radiation treatments, after which damage can appear months or years after initial treatment. Severity of damage depends on how much of the lung was exposed to radiation, total amount of radiation administered, whether chemotherapy also was used, presence of underlying lung disease.
- Medications, including chemotherapy drugs such as methotrexate and cyclophosphamide, some drugs used to treat irregular heartbeats such as amiodarone or propranolol, some antibiotics such as nitrofurantoin and sulfasalazine.
- Medical conditions, including systemic lupus erythematosus, rheumatoid arthritis, sarcoidosis or scleroderma.
Although the condition has been found in children and infants, it is much more likely to affect middle-aged and older adults, particularly those with a history of smoking. People who work in mining, farming or other occupations that regularly expose them to pollutants are also more susceptible to pulmonary fibrosis.