Obstructive vs Restrictive Lung Disease

Lung diseases are disorders that negatively affect the lungs. To classify what kind of condition a patient has, doctors must first determine if it’s an obstructive or restrictive lung disease. Spotting the differences between obstructive vs restrictive lung disease may be difficult at first glance. Here’s what you need to know about the two types of lung conditions.

Causes of obstructive and restrictive lung disease

In general, obstructive lung diseases make it hard for a person to expel all the air from their lungs. People with restrictive lung diseases, on the other hand, have trouble fully filling their lungs with air.

Obstructive lung disease occurs when the airways become inflamed and swell up, causing it to narrow significantly. When the airways shrink, exhalation slows down, which leaves an unusual volume of air in the lungs. The increase in breathing rate during exertion barely gives the lungs enough time to expel air. That is why, during strenuous activities, people with an obstructive lung disease find it more difficult to breathe.

Meanwhile, restrictive lung disease are disorders that can reduce lung volume. This can be attributed to the weakening of the muscles,  nerve damage, or secondary inflammation of lung tissues from conditions like interstitial lung diseases (ILD). A person with a restrictive lung disease finds it hard to fully expand their lungs when breathing in. Also, restrictive lung disease is linked to a decrease in lung capacity.

Lung conditions characterized as obstructive or restrictive

Obstructive

Some of the lung diseases that are classified as obstructive are:

• Chronic obstructive pulmonary disease (COPD). This refers to a cluster of lung conditions that result in breathing difficulties. Emphysema and chronic bronchitis fall under COPD.
• Asthma. This causes chronic inflammation of the airways.
• Bronchiectasis. Marked by an abnormal widening of the lungs, bronchiectasis leads to mucus build-up. This makes the lungs more vulnerable to infections.
• Bronchiolitis. This usually occurs due to a virus that causes inflammation and congestion in the bronchioles. This lung infection is prevalent in infants and young children.
• Cystic fibrosis (CF). This is a hereditary, chronic, and potentially life-threatening condition that affects a person’s respiratory and digestive systems. CF affects the secretion of bodily fluid by making them thick and sticky, thus blocking passageways in the lungs and pancreas.

Restrictive

Lung conditions classified as restrictive are:

• Pneumoconiosis. This is a type of lung disease that is triggered by inhaling dust particles that injure the lungs.
• Eosinophilic pneumonia. This refers to lung diseases in which eosinophil, a type of white blood cell, is present in high numbers in the lungs.
• Sarcoidosis. A rare inflammatory disease, sarcoidosis occurs when swollen tissues (granulomas) grow in different organs in the body.
• Pulmonary fibrosis and idiopathic pulmonary fibrosis. These refer to scarring or damage in the lung tissues. Stiffened scar tissue makes the lungs work twice as hard and can cause shortness of breath.
• Asbestosis. This lung condition occurs when a person inhales asbestos. Asbestosis leads to long-term scarring and inflammation in the lungs.
• Silicosis. People with silicosis suffer from breathing problems caused by frequent inhalation of silica-containing dust particles. These particles can block the airways and cause inflammation and scarring.

Obstructive or restrictive

Some lung diseases can be either obstructive or restrictive:

• Pneumonia. This is characterized by the inflammation of the air sacs in one or both lungs due to bacterial, viral, or fungal infection.
• Acute respiratory distress syndrome (ARDS). This is a severe lung disease that happens when fluids build-up in the air sacs of the lungs. The fluid hinders the lungs from retaining more air, thus decreasing the amount of oxygen in the bloodstream.
• Tuberculosis (TB). This very transmissible disease is caused by the bacterium Mycobacterium tuberculosis. It commonly targets the lungs, but can also infect other organs.

Diagnosis

To identify what type of lung disease a patient has, doctors usually suggest pulmonary function tests (PFTs) or tests that measure how well a person’s lungs are working. These are done by blowing air into a spirometer, which calculates how much air you breathe in and out and how long it takes for you to exhale. A spirometry test will help determine the type and severity of the lung disease.

Additionally, doctors may recommend that patients undergo more tests to confirm the diagnosis:

• Pulse oximetry and/or arterial blood gas. This test measures the saturation of oxygen in the blood.
• Imaging tests like a chest x-ray and CT scans. These provide a better visualization of the lung tissue and other structures.
• Bronchoscopy. This procedure is done by inserting a bronchoscope through the nose, down the throat, and into the lungs. This lets the doctors see the situation inside a patient’s airways.

Key takeaways

The difference between obstructive vs restrictive lung disease is quite hard to spot since they exhibit almost the same symptoms. If you’ve been experiencing shortness of breath or difficulty breathing, it is best to consult a doctor right away to get an official diagnosis.

While most obstructive and restrictive lung diseases aren’t curable, there are a lot of treatments that can help manage the symptoms.

Learn more about Other Respiratory Issues here.