Scars on the lung tissue cause it to thicken and lose the elasticity found in healthy lungs.
Like scars on the skin, lung scars are permanent. Small scars may not cause noticeable symptoms, but excessive scarring makes it difficult for the lungs to transfer oxygen into the bloodstream. This means the brain and other organs may not receive the oxygen they need.
In this article, we look at treatment and prevention of lung scarring, as well as some causes and symptoms.
Several conditions can cause scarring of the lungs.
Interstitial lung disease (ILD) is characterized by inflammation of the air sacs or the web of tissue surrounding the air sacs (interstitium) in the lungs. The inflammation can sometimes lead to buildup of scar tissue within the lungs, resulting in fibrosis.
ILD is most often idiopathic, meaning that its exact cause is unknown. Idiopathic pulmonary fibrosis (IPF) is the most common form. It typically affects people aged 70-75 years old and is very rare in those under the age of 50.
Around 1 in 20 people with IPF have a close relative with the condition. Risk factors for IPF include:
- a viral infection
- acid reflux from the stomach into the lungs
- sex, as diagnosis is more common in men
Previous infections can also cause scars on the lungs. These infections include:
Other conditions associated with causing lung scars over time include:
- cystic fibrosis
Scarring of the lungs can also be the side effect of certain types of cancer treatment. Chemotherapy drugs can damage the lungs, while radiation is more likely to cause damage if it is to the chest cavity.
Types of cancer that may require radiation to the chest cavity include breast cancer, lung cancer, and Hodgkin's lymphoma. It can take up to 2 to 3 months after radiation treatment for symptoms to occur.
Lung scarring can also be a side effect of other medications.
Medications that can cause fibrosis in the lungs include:
- cytotoxic agents (bleomycin, methotrexate)
- antiarrhythmic drugs (amiodarone)
- antibiotics (nitrofurantoin, sulfonamides)
The scarring of the lung tissue makes it thick and stiff. As the lung tissue thickens, it becomes increasingly harder to transfer oxygen from the lungs into the bloodstream. As a result, the brain and other organs do not receive enough oxygen.
Symptoms of lung scarring are relative to the extent of the scarring and how much of the lung is affected.
- shortness of breath, especially during or after physical activity
- a persistent dry cough
- weight loss and loss of appetite
- rounded and swollen fingertips and nails (clubbing)
- night sweats
In cases of IPF, scarring usually begins at the edge of the lungs and gradually works its way to the center.
Symptoms of IPF usually develop gradually and worsen over time. Often people do not notice any signs until the disease is well established.
As IPF is more common in older people, it may be more difficult to identify what is causing the symptoms. However, if light activity is causing a person to have difficulty breathing or feel out of breath, they should see their doctor as soon as possible.
Just like scars on the skin, scars on the lung are permanent and cannot usually be removed. The lungs are resilient, however, and can often deal with small scars without any adverse effects.
Proper diagnosis and monitoring of the scars is key to treatment. If scars remain unchanged for 2 years or more, it generally means they were caused by an old infection and are harmless.
However, if lung scars have spread, they could be the sign of something more serious, such as pulmonary fibrosis.
There is currently no cure for pulmonary fibrosis, but there are treatment options available for relieving symptoms and slowing its progression. These include:
- quitting smoking
- eating a healthful and varied diet
- doing moderate exercise
- taking medication to stop the scarring from getting worse
- breathing oxygen through a mask
- practicing pulmonary rehabilitation
- having a lung transplant, in severe cases
There are many lifestyle changes that people with lung scarring can make to reduce the severity of their symptoms. It is important to consult with a doctor before making any changes.
These changes can include:
- quitting smoking to increase oxygen levels in the blood
- exercising regularly
- losing weight to improve breathing capacity
- taking precautions to prevent catching an infection from others
- avoiding excessive pollutants and dust
The outlook for people with lung scarring will depend entirely on the cause of the scarring and the health of the individual.
Scarring caused by infection is usually harmless, depending on the extent of the scarring. Once the person has recovered from the infection, they may want to monitor the scarring and the associated symptoms.
Symptoms of IPF will get worse over time, although the speed of this can vary. Some people live relatively symptom-free for years, while others find that their breathlessness progresses more rapidly and becomes debilitating.
There is no cure for IPF other than a lung transplant, but certain medications may slow the progression of disease or provide symptom relief.
People with extensive lung scars will need to be regularly monitored. The life expectancy of people with conditions associated with lung scarring varies greatly depending on the underlying condition and the individual's age.
Anyone dealing with a life-altering condition is advised to seek support from friends, family, healthcare providers, and support groups. People with conditions such as IPF should also ensure they do not to overexert themselves and get plenty of rest.