What Is Meant By Restrictive Lung Diseases?
Chronic lung conditions, which restrict the ability of an individual’s lungs to expand while inhaling, are known as Restrictive Lung Diseases.(1)
Restrictive lung disease is a condition that specifically targets the ability to inhale by restricting the lung expansion when a person is breathing.(2)
While majority of the restrictive lung diseases have no cure, they can be managed with medication and exercise programs. Long-term lung conditions are categorized under 2 headings depending on how a person’s breathing is affected by them and these categories are either restrictive or obstructive.
There is a third category known as the mixed lung disease, which is smaller and comprises of characteristics of both restrictive and obstructive lung diseases.
Who Develops Mixed Lung Disease?
Differentiation Between Obstructive Lung Diseases and Restrictive Lung Diseases(3)
Obstructive lung diseases, such as asthma, restrict normal exhalation. Whereas, on the contrary, restrictive lung diseases hinder normal inhalation by limiting the capacity of the lungs to expand to their fullest when a person inhales.
Restrictive lung diseases, on the other hand, mean the lungs are unable to fully expand, so they limit the amount of oxygen taken in during inhalation(4). Restrictive lung diseases mean decreased lung expansion or capacity or volume that result in increased breathing rate to meet oxygen demands of the patient. This limitation also restricts the air that can be exhaled when compared to a healthy person.
Types of Restrictive Lung Diseases
There are 2 types of restrictive lung diseases and the type depends on nature of its cause; whether it’s extrinsic or intrinsic.(1, 4)
Intrinsic Restrictive Lung Disorders
Intrinsic Restrictive Lung Disorders are characterized by internal abnormality often causing inflammation, stiffening and scarring of the tissues of the lungs.
Intrinsic restrictive lung diseases include the following conditions: tuberculosis, pneumonia, idiopathic pulmonary fibrosis, sarcoidosis, lung cancers, interstitial lung disease, rheumatoid arthritis, fibrosis resulting from radiation; inflammatory bowel disease (IBD); infant and acute respiratory distress syndrome and systemic lupus.(3)
Extrinsic Restrictive Lung Disease
The cause of extrinsic restrictive lung disease is complications with structures located outside the lungs or tissues; and also includes neurological conditions. The cause of extrinsic restrictive lung disease is external factors that are usually associated with damaged nerves, weakened muscles or stiffening of the tissues of the chest wall.(3)
Extrinsic restrictive lung diseases consist of the following conditions: scoliosis, pleural effusions, neuromuscular disease or conditions (Lou Gehrig’s disease, MS, ALS etc.), obesity, malignant tumors, myasthenia gravis, rib injury, such as fractures; swelling in the abdomen related to liver cancer/scarring; ascites, heart failure, kyphosis, diaphragmatic hernia or diaphragm paralysis.
What are the Symptoms of Restrictive Lung Diseases?(4)
Some of the common symptoms of restrictive lung diseases are:
- Patient’s inability to catch breath or get sufficient breath.
- Shortness of breath, especially with exertion.
- Chronic cough, often dry; however can be accompanied by mucus or white sputum.
- Chest pain.
- Weight loss.
- Gasping breath or wheezing.
- Extreme fatigue without any clear reason.
- Anxiety and depression.
Do Restrictive Lung Diseases Get Better With Time?
No, as a matter of fact, many of the restrictive lung diseases are progressive in nature that is they worsen over a period of time.
How is Restrictive Lung Diseases Diagnosed?
Various tests are done to diagnose restrictive lung disease, such as scans and x-ray.
A pulmonary function test is also done to measure the patient’s total lung capacity or the total amount of air taken in by the lungs during inhalation. In case of restrictive lung disease, there is reduction in the total lung capacity.(4)
Depending on the potential cause of restrictive lung disease, the doctor will order other tests and come up with the right treatment plan for the patient. If the tests done show decreased lung function, then this can indicate that a large portion of the lungs is affected by stiffening, inflammation or scarring.
Tests That Are Commonly Done For Diagnosis Of Restrictive Lung Disease Are:
Forced Vital Capacity (FVC) Test: In this test, the patient is asked to inhale and fill the lungs with as much air as possible; after which the patient is told to exhale with as much force as possible. Patients suffering from restrictive lung diseases will have decreased FVC value of equal to or less than 80%.
Forced Expiratory Volume in 1 Second (FEV1) Test: This test measures the quantity of air expelled by the patient during the first second of the FVC test. Many patients are able to exhale around three-quarters of the inhaled air. However, in case of restrictive lung disease, as the FVC is reduced, so the FEV1 will be low accordingly.
FEVI to FVC Ratio Test: This is a test that compares the quantity of air exhaled in the first second of exhalation (FEV1) to the quantity of air expelled during an FVC test. This ratio can be increased or is usually normal in patients suffering from restrictive lung disease.
Chest X-ray: This test generates images of the lung area and the entire chest for assessment for restrictive lung disease.
Computed Tomography (CT) Scans: CT scan produce more detailed images of the lung area and chest; and benefits greatly in diagnosis of restrictive lung disease.
Bronchoscopy(5): In this test, a flexible tube with a camera attached is inserted into the airways of the lungs via the nose or mouth for examination.
What is the Treatment for Restrictive Lung Disease?
Treatment depends on the type and cause of the restrictive lung disease.
Oxygen Therapy (1, 4): In some patients, treatment only requires oxygen therapy to help the patient breathe properly.
Medications (4): Medications used for treatment of restrictive lung diseases are: cyclophosphamide, azathioprine, methotrexate, corticosteroids (often in inhaler form) and also other anti-inflammatory and immunosuppressant medications. Anti-scarring medications, such as nintedanib or pirfenidone can also be used.(1)
Surgery (1, 4): Surgery may be needed in severe cases of restrictive lung disease and includes: corrective surgery, lung transplant surgery or stem cell therapy.
Is It Possible To Reverse The Damage Caused By Restrictive Lung Disease?
Unfortunately, the damage done in restrictive lung diseases is usually irreversible and includes: scarring, loss of elasticity or thickening.
Ways to Reduce and Manage Symptoms of Restrictive Lung Diseases
- Quitting smoking is one major lifestyle change that a patient suffering from restrictive lung disease should mandatorily follow if he/she values their life.
- Lifestyle changes along with doing at-home exercises helps greatly in reducing the degree of symptoms of restrictive lung disease.
- Breath conditioning that includes slow-deep breathing, pursed lip breathing or diaphragmatic breathing helps a lot to alleviate the impact of restrictive lung disease.
- Respiratory muscle strengthening exercises should be done to help with the symptoms of restrictive lung disease.
- Level walking, visualized meditation and relaxation help a lot in managing the symptoms of restrictive lung disease.
- Strengthening and conditioning exercises of the upper and lower limbs also help.
- When suffering from restrictive lung disease, it is important to avoiding environments that contain irritants, toxins or allergens, which can cause worsening of the symptoms.
It is important that patients suffering from restrictive lung disease consume a balanced and nutritious diet.