What disease is a condition of altered airflow through the lungs generally caused by airway obstruction due to mucus production quizlet?

One of the first steps in diagnosing lung diseases is differentiating between obstructive lung disease and restrictive lung disease. While both types can cause shortness of breath, obstructive lung diseases, such as asthma and chronic obstructive pulmonary disorder (COPD), cause more difficulty with exhaling air, while restrictive lung diseases (such as pulmonary fibrosis) can cause problems by restricting a person's ability to inhale air.

It’s a difference that might not be obvious, but the treatments differ, and diagnostic tests can distinguish between these two different categories of lung disease.

Causes

There are many different obstructive and restrictive lung diseases.

Click Play to Learn the Difference Between Obstructive vs. Restrictive Lung Disease

Obstructive

Obstructive lung diseases are characterized by an obstruction in the air passages, with slow and shallow exhalation.

Obstruction can occur when inflammation and swelling cause the airways to become narrowed or blocked, making it difficult to expel air from the lungs. This results in an abnormally high volume of air being left in the lungs (i.e., increased residual volume). This leads to trapped air and lung hyperinflation—changes that contribute to worsening respiratory symptoms.

The following lung diseases are categorized as obstructive:

• Chronic obstructive pulmonary disease (COPD)
• Chronic bronchitis
• Asthma
• Bronchiectasis
• Bronchiolitis
• Cystic fibrosis

Restrictive

In contrast to obstructive lung diseases, restrictive conditions are defined by difficulty filling the lungs with air during inhalation. Restrictive lung diseases are characterized by a reduced total lung capacity.

Restrictive lung diseases can be due to either intrinsic, extrinsic, or neurological factors.

Intrinsic Restrictive Lung Diseases

Intrinsic restrictive disorders are those that occur due to restriction in the lungs (often a "stiffening") and include:

• Pneumonia
• Pneumoconioses
• Acute respiratory distress syndrome (ARDS)
• Eosinophilic pneumonia
• Tuberculosis
• Sarcoidosis
• Pulmonary fibrosis and idiopathic pulmonary fibrosis
• Lobectomy and pneumonectomy (lung cancer surgery)

Extrinsic Restrictive Lung Diseases

Extrinsic restrictive disorders refer to those that originate outside of the lungs. These include impairment caused by:

• Scoliosis
• Obesity
• Pleural effusion
• Malignant tumors
• Ascites
• Pleurisy
• Rib fractures

Neurological Restrictive Lung Diseases

Neurological restrictive disorders are those caused by disorders of the central nervous system that interfere with movements necessary to draw air into the lungs.

Among the most common causes:

• Paralysis of the diaphragm
• Guillain-Barré syndrome
• Myasthenia gravis
• Muscular dystrophy
• Amyotrophic lateral sclerosis (ALS or Lou Gehrig's Disease)

A person may also have symptoms and tests that suggest a combination of obstructive and restrictive disease (for example, when a person has both COPD and pneumonia). In addition, some diseases, such as silicosis, cause an obstructive pattern in the early stages of the disease and a restrictive pattern when the condition is more advanced.

Symptoms

There can be a significant overlap in symptoms between obstructive and restrictive lung diseases, which is why pulmonary function tests are often needed to make a diagnosis.

Symptoms shared by both obstructive and restrictive conditions include:

• Dyspnea (shortness of breath)
• Persistent cough
• Tachypnea (rapid respiratory rate)
• Anxiety
• Unintentional weight loss (due to the increased energy needed to breathe)

Obstructive Symptoms

With obstruction, a person may have difficulty expelling all of the air from the lungs. This often worsens with activity. When respiratory rate increases, it becomes challenging to blow out all of the air in the lungs before taking the next breath.

Narrowing of the airways may cause wheezing, as well as increased mucus (sputum) production.

Restrictive Symptoms

With restrictive lung disease, a person may feel like it is hard to take a full breath, and this can cause considerable anxiety at times.

With extrinsic lung disease, a person may change positions trying to find a one that makes it easier to breathe.

Obstructive Disease Symptoms

• Lungs may feel chronically full or part full

• Wheezing

• Mucus production

Restrictive Disease Symptoms

• Feels hard to breathe enough air

• Breathing difficulties may cause panic

• May change positions to attempt to make it easier to breathe (extrinsic cases)

Diagnosis

Making a diagnosis of either obstructive or restrictive lung disease begins with a careful history and physical exam. Pulmonary function tests and imaging tests are an important part of the diagnostic process.

These tests can also help doctors understand if more than one condition is present at the same time, especially when a mixed pattern is found.

Pulmonary Function Tests

Spirometry is a common office test used to evaluate how well your lungs function by measuring how much air you inhale and how much/how quickly you exhale. It can be helpful in differentiating obstructive and restrictive lung diseases, as well as determining the severity of these diseases.

This test can determine the following:

• Forced vital capacity (FVC): Forced vital capacity measures the amount of air you can breathe out forcefully after taking as deep a breath as possible.
• Forced expiratory volume in one second (FEV1):  This test measures the total amount of air that can be forcibly exhaled in the first second of the FVC test. Healthy people generally expel around 75% to 85% in this time. The FEV1 is decreased in obstructive lung diseases and normal to minimally decreased in restrictive lung diseases.
• FEV1/FVC ratio: The ratio of FEV1 to FVC measures the amount of air a person can forcefully exhale in one second relative to the total amount of air they can exhale. This ratio is decreased in obstructive lung disorders and normal in restrictive lung disorders. In an adult, a normal FEV1/FVC ratio is 70% to 80%; in a child, a normal ratio is 85% or greater. The FEV1/FVC ratio can also be used to figure out the severity of obstructive lung disease.
• Total lung capacity (TLC): Total lung capacity (TLC) is calculated by adding the volume of air left in the lungs after exhalation (the residual volume) to the FVC. TLC is normal or increased in obstructive defects and decreased in restrictive ones. In obstructive lung diseases, air is left in the lungs (air trapping or hyperinflation), causing a TLC increase.

There are other types of pulmonary function tests that may be needed as well:

• Lung plethysmography estimates the amount of air that is left in the lungs after expiration (functional residual capacity) and can be helpful when there is overlap with other pulmonary function tests. It estimates how much air is left in the lungs (residual capacity), which is a measure of the compliance of the lungs. With restrictive airway disease, the lungs are often "stiffer" or less compliant.
• Diffusing capacity (DLCO) measures how well oxygen and carbon dioxide can diffuse between alveoli (the tiny air sacs) and capillaries (small blood vessels) in the lungs. The number may be low in some restrictive lung diseases (for example, pulmonary fibrosis) because the membrane is thicker; it may be low in some obstructive diseases (for example, emphysema) because there is less surface area for this gas exchange to take place.

Obstructive and Restrictive Lung Patterns

Laboratory Tests

Lab tests may give an indication of the severity of lung disease, but are not very helpful in determining if it is obstructive or restrictive in nature.

Oximetry, a measure of the oxygen content in the blood, may be low in both types of diseases. Arterial blood gases may also reveal a low oxygen level and, sometimes, hypercapnia (elevated carbon dioxide level). With chronic lung disease, hemoglobin levels are often elevated in an attempt to carry more oxygen to the cells of the body.

Imaging Studies

Tests such as chest X-ray or chest computed tomography (CT) scan may give clues as to whether a lung disease is obstructive or restrictive if the underlying condition, such as pneumonia or a rib fracture, can be diagnosed with the help of such imaging.

Procedures

Bronchoscopy is a test in which a lighted tube with a camera is threaded through the mouth and down into the large airways. Like imaging studies, it can sometimes help diagnose the underlying condition.

The treatment options are significantly different for obstructive and restrictive lung diseases, though treatments also vary depending on the particular root cause.

With obstructive lung diseases such as COPD and asthma, medications that dilate the airways (bronchodilators) can reduce symptoms. Inhaled or oral steroids are also frequently used to reduce inflammation.

Treatment options for restrictive lung diseases are more limited:

• With extrinsic restrictive lung disease, treatment of the underlying cause, such as a pleural effusion or ascites, may result in improvement.
• With intrinsic restrictive lung disease such as pneumonia, treatment of the condition may also help.
• Until recently, there was little that could be done to treat idiopathic fibrosis, but there are now drugs available that can reduce the severity.

Supportive treatment can be helpful for both types of lung diseases and may include supplemental oxygen, noninvasive ventilation (such as CPAP or BiPAP), or mechanical ventilation. Pulmonary rehabilitation may be beneficial for people who have COPD or who have had lung cancer surgery.

When severe, lung transplantation is also sometimes an option.

Prognosis

The prognosis of obstructive vs restrictive lung diseases depends more on the specific condition than the category of lung disease. With obstructive lung diseases, those that are reversible often have a better prognosis than those that are not.

A Word From Verywell

Getting an accurate diagnosis of your lung disease is important for determining the next steps in your treatment. Find a healthcare team you trust and make sure to keep lines of communication open, asking questions and seeking answers so that you're empowered to take charge of your health.

Frequently Asked Questions

• Is asthma a restrictive or obstructive lung disease?

  Asthma is an obstructive lung disease. Inflammation of the airways causes swelling and excess mucus production, which prevents air from passing through and can result in an asthma attack. Many people with asthma take inhaled corticosteroids to control this inflammation and regain normal breathing.

• How is restrictive lung disease treated?

  The specific type of disease or condition will affect how it should be treated. Restrictive lung disease treatment may involve antibiotics, inhalers, chemotherapy, expectorants (type of cough medicine), lung transplantation, and oxygen therapy.

• What does ARDS stand for?

  Acute respiratory distress syndrome (ARDS) is a lung condition that causes hypoxemia, which is a low level of oxygen in the blood. ARDS symptoms can include shortness of breath, rapid breathing, confusion, drowsiness, and bluish-colored hands and feet.

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

1. Mangera Z, Panesar G, Makker H. Practical approach to management of respiratory complications in neurological disorders. Int J Gen Med. 2012;5:255-63. doi:10.2147/IJGM.S26333

2. Johnson JD, Theurer WM. A stepwise approach to the interpretation of pulmonary function tests. Am Fam Physician. 2014;89(5):359-66.

3. Scelfo C, Caminati A, Harari S. Recent advances in managing idiopathic pulmonary fibrosis. F1000Res. 2017;6:2052. doi:10.12688/f1000research.10720.1

4. The University of Chicago: Asthma & COPD Center. How Asthma Works.

5. Johns Hopkins Medicine. Restrictive Lung Disease.

6. National Heart, Lung, and Blood Institute. Acute Respiratory Distress Syndrome.

Additional Reading

• Kasper DL, Fauci AS, Hauser SL. Harrison's Principles of Internal Medicine. New York: McGraw Hill Education, 2015. Print.

• Kumar V, Abbas AK, Aster JC. Robbins and Cotran Pathologic Basis of Disease. Philadelphia: Elsevier-Saunders, 2015. Print.

• McCormack M. Overview of Pulmonary Function Testing in Adults. UpToDate.

By Deborah Leader, RN
 Deborah Leader RN, PHN, is a registered nurse and medical writer who focuses on COPD.

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