Obstructive vs. Restrictive Lung Disease: Understanding the Difference
Recently, the question came up in our community here at Asthma.net about the difference between obstructive lung disease and restrictive lung diseases. These are the two major types of lung disease.1 So, this article will help you understand what these types of respiratory diseases are and how they are both similar and different.
Knowing the difference between these types of chronic respiratory conditions can help you and your health care team manage your health both now and into the future.
Defining obstructive vs. restrictive
Obstructive lung disease is a condition where the airflow into and out of the lungs is impeded.1 This occurs when inflammation causes the airways to swell, making them narrower. Because of that, breathing well becomes harder and air often gets trapped in the lungs. This results in something known as hyperinflation of the lungs. Exhaling becomes slower and shallower than in a person with a healthy respiratory system.
Examples of obstructive lung disease include1:
- COPD (Chronic obstructive pulmonary disease), which includes emphysema and bronchitis
Restrictive lung disease is a condition where the lungs don’t function effectively. People with this cannot take a full, deep breath and fill their lungs with air. This can be due to problems within the lungs themselves (intrinsic) or due to some kind of damage from external forces (extrinsic).
With intrinsic disorders, the lungs’ restriction is related to weak muscles, stiffness in the chest wall or damaged nerves.1 Examples of these diseases include:
- Interstitial lung disease
- Pulmonary fibrosis
With extrinsic disorders, other non-respiratory diseases end up causing problems with the function of the airways and lungs. These can include:
- Pleural effusion
- Myasthenia gravis
- Neuromuscular diseases, such as muscular dystrophy or Lou Gehrig’s Disease (ALS)
How obstructive and restrictive lung diseases are similar
Both of these types of lung disease can have some of the same symptoms, such as:
- Shortness of breath
- Chronic cough
Also, both obstructive and restrictive disease will be diagnosed by using a careful medical history and a variety of pulmonary function tests. The results of those tests and your history will help a doctor determine which type of lung disease you might have.
In general, both types of disease can be progressive and worsen over time, although this is not true of all conditions. How quickly that occurs depends greatly on your stage or level of illness at the time you are diagnosed, as well as other health factors such as age. But both kinds of disease are treatable and the progression can be slowed.
There are varying levels or stages assigned to both restrictive and obstructive lung disease, ranging from mild to severe. However, keep in mind that different measures are used to place people into those stages.
How they differ
The main way these two types of respiratory illness differ is that1:
- Obstructive diseases make it hard to exhale all the air from your lungs.
- Restrictive diseases make it hard to fill the lungs with air.
Although some of the symptoms are the same, the actual quality of those symptoms can differ. For example, COPD, which is an obstructive disease, usually has a chronic cough that includes excess mucus. On the other hand, restrictive diseases tend to have more of a dry cough. However, asthma, which is obstructive, also tends more to a dry cough than a “wet” one.
Other symptoms typical for obstructive disease include:
- Chest tightness
- Frequent respiratory infections
Symptoms that can occur with restrictive disease may also include1:
- Weight loss
- Achy joints
Lung diseases affect each person differently. You can also see that there are a variety of factors in the actual different types of obstructive and restrictive conditions. So prognosis and life expectancy can vary widely. It’s easy to see that although there are similarities between both COPD and asthma (both obstructive), the outcomes can be quite different. Asthma, except for the severe persistent type, could be milder, less progressive and affect the quality of life much less than COPD does.
So, your best bet is to discuss your disease with your doctor. Don’t be afraid to ask questions about what to expect as far as the course of your illness and how it will affect you going into the future.
Treatment Options for Each
Treatment options will be somewhat different for these two types of respiratory illness.1 With obstructive lung disease, the goal is to reduce inflammation and relax the airways. So, treatments might include bronchodilators and/or inhaled steroids. Some medications are long-acting and some are shorter-acting.
In addition, with COPD, supplemental oxygen therapy might be helpful. This is not generally prescribed in people who have asthma. Changes in lifestyle may also be helpful. For example, with asthma, learning to avoid your triggers can help keep your asthma under control.
With restrictive lung disease, the treatment options are often more limited. They may also vary greatly, depending on the specific type of restrictive disease. Steroids and bronchodilators are sometimes used. Medications that suppress the immune system may also be helpful.1 Other options might include supportive oxygen therapy and even lung transplants.
If you’re having trouble breathing but don’t know why yet, it can be frustrating waiting for your doctor to figure out exactly what is going on. It may take some time and a lot of tests before you get a definite diagnosis.
However, when your doctor knows whether you have an obstructive or restrictive lung disease, then s/he will be better able to put together the best treatment plan for you and your airways. And that helps to ensure that your respiratory health improves and stabilizes and that you are able to live your best life.