Interstitial lung disease includes more than 200 different conditions that cause inflammation and scarring around the balloon-like air sacs in your lungs, called the alveoli. Oxygen travels through the alveoli into your bloodstream. When they’re scarred, these sacs can’t expand as much. As a result, less oxygen enters your blood.
Other parts of your lungs can be affected too, such as the airways, lung lining, and blood vessels.
Life expectancy and prognosis
Interstitial lung disease can vary from person to person and depending on what caused it. Sometimes it progresses slowly. In other cases, it worsens quickly. Your symptoms can range from mild to severe.
Some interstitial lung diseases have a better prognosis than others. One of the most common types, called idiopathic pulmonary fibrosis, can have a limited outlook. The average survival for people with this type is currently 3 to 5 years. It can be longer with certain medications and depending on its course. People with other types of interstitial lung disease, like sarcoidosis, can live much longer.
While getting a lung transplant can improve your survival, future medications will likely offer the best solutions for most people.
Interstitial lung disease comes in more than 200 different types. Some of these include:
- asbestosis: inflammation and scarring in the lungs caused by breathing in asbestos fibers
- bronchiolitis obliterans: a condition that causes blockages in the smallest airways of the lungs, called bronchioles
- coal worker’s pneumoconiosis: a lung condition caused by exposure to coal dust (also called black lung disease)
- chronic silicosis: a lung disease caused by breathing in the mineral silica
- connective tissue-related pulmonary fibrosis: a lung disease that affects some people with connective tissue diseases such as scleroderma or Sjögren syndrome
- desquamative interstitial pneumonitis: a condition that causes lung inflammation and that is more common in people who smoke
- familial pulmonary fibrosis: a buildup of scar tissue in the lungs that affects two or more members of the same family
- hypersensitivity pneumonitis: inflammation of the alveoli caused by breathing in allergic substances or other irritants
- idiopathic pulmonary fibrosis: a disease of unknown cause in which scar tissue develops throughout the lung tissue
- sarcoidosis: a disease that causes small clumps of inflammatory cells to form in organs such as the lungs and lymph glands
Symptoms of interstitial lung disease
When you have interstitial lung disease, you can’t get enough oxygen into your blood. As a result, you feel short of breath, especially when you exercise or climb stairs. Eventually, you may find it hard to breathe, even at rest.
A dry cough is another symptom. Symptoms often get worse over time.
See your doctor if you have trouble breathing. After a diagnosis, you can start treatments to manage the inflammation and scarring.
Causes of interstitial lung disease
Many times, doctors can’t find the cause of interstitial lung disease. In these cases, the condition is called idiopathic interstitial lung disease.
Other causes of interstitial lung disease include medical conditions, use of some drugs, or exposure to toxic substances that damage your lungs. These causes of interstitial lung disease fall into three main categories:
Your body’s immune system attacks and damages the lungs and other organs in these conditions:
- dermatomyositis: an inflammatory disease that causes muscle weakness and skin rash
- lupus: a condition in which the immune system attacks many types of tissue, including the skin, joints, and other organs
- mixed connective tissue disease: a condition that has symptoms of several connective tissue diseases, including polymyositis, lupus, and scleroderma
- polymyositis: a condition that causes inflammation of the muscles
- vasculitis: inflammation and damage to blood vessels in the body
- rheumatoid arthritis: a disease in which the immune system attacks the joints, lungs, and other organs
- scleroderma: a group of diseases that cause the skin and connective tissue to thicken and tighten
- Sjögren syndrome: a condition that causes joint pain, dry eyes, and dry mouth
Exposure to toxic substances
Exposure to the following substances at work or in the environment can cause lung scarring as well:
- animal proteins, such as from birds
- asbestos fibers
- coal dust
- grain dust
- silica dust
- tobacco smoke
Medication and drugs
In people who are susceptible, all of these drugs can damage the lungs:
- antibiotics such as nitrofurantoin (Macrobid, Macrodantin) and sulfasalazine (Azulfidine)
- anti-inflammatories such as aspirin, etanercept (Enbrel), and infliximab (Remicade)
- chemotherapy drugs such as azathioprine (Imuran), bleomycin, cyclophosphamide, methotrexate (Trexall), and vinblastine
- heart medications such as amiodarone (Cordarone, Nexterone, Pacerone)
- drugs such as heroin and its treatment, methadone
Treatments can’t reverse lung damage, but they can slow disease progression and help you breathe more easily. If exposure to a toxic material or drug caused your interstitial lung disease, avoid that substance.
Your doctor can prescribe a few different types of treatments to manage interstitial lung disease:
- Supplemental oxygen is currently recommended in the international guidelines for treatment, although no studies have proven its benefit. Individuals report feeling less breathless with its use.
- Pulmonary rehabilitation may help improve your activity levels and ability to exercise.
- Anti-inflammatory drugs, such as the steroid prednisone, can reduce swelling in the lungs.
- Immune-suppressing drugs, such as azathioprine (Imuran), cyclophosphamide (Cytoxan), and mycophenolate mofetil (CellCept), may help stop the immune system attacks that damage the lungs.
- Antifibrotic drugs such as pirfenidone (Esbriet) and nintedanib (Ovef) may prevent further scarring in the lungs. These drugs are both approved by the U.S. Food and Drug Administration for the treatment of idiopathic pulmonary fibrosis.
If your condition is severe and other treatments don’t help, the last resort is to have a lung transplant. However, a transplant is not a cure. Typically, this surgery is recommended if you’re younger than 65 years, but in some cases you can be older. You can’t have other major health conditions, such as cancer, HIV, hepatitis B or C, or heart, kidney, or liver failure.
While you’re undergoing treatment, here are a few things you can do to stay healthy:
- Stop smoking. Smoking can damage your lungs even more.
- Eat a well-balanced diet. Getting enough nutrients and calories is important, especially because this disease can make you lose weight.
- Exercise. Using oxygen can help you stay active.
- Get your vaccines for pneumonia, whooping cough, and flu. These infections can worsen your lung symptoms.
Scarring in your lungs can’t be reversed. Still, treatments can slow lung damage and help you breathe more easily. Lung transplant remains an option for those who don’t respond to other medical treatment.