What to know about obstructive lung disease
Blockages damage the lungs and cause their airways to narrow. This damage leads to difficulty breathing.
In this article, we look at the causes, symptoms, diagnosis, and treatment of several types of obstructive lung disease.
What is obstructive lung disease?
When a person with healthy lungs breathes, gas exchange occurs in air sacs called alveoli.
When a person breathes, air travels down the windpipe through a series of tubes called bronchi, which gradually get smaller. At the end of these tubes are bunches of air sacs called alveoli.
In healthy lungs, the alveoli fill up with air and pass oxygen through to the blood vessels that run along them. At the same time, the blood passes carbon dioxide back to the alveoli for exhalation.
In obstructive lung disease, less air flows in and out of the alveoli and fewer gas exchanges can happen. This can happen for many reasons, depending on which type of obstructive lung disease a person has.
Types of obstructive lung disease include:
Obstructive vs. restrictive lung disease
While many of the symptoms of obstructive lung disease and restrictive lung disease are similar, the causes of the symptoms differ.
When a person has obstructive lung disease, something prevents air from flowing as freely in and out of the airways.
Common factors that obstruct airflow include:
- swelling and inflammation in the airways
- thick mucus in the airways
- damage to the walls of the air sacs
In restrictive lung diseases, a person cannot fully fill their lungs because the lungs are restricted. Conditions that cause stiffness in the lungs or the muscles around the lungs cause restrictive lung disease.
Conditions that cause restrictive lung disease include:
- muscular dystrophy
- interstitial lung disease
- neuromuscular disease, such as amyotrophic lateral sclerosis
- pulmonary fibrosis
Symptoms of obstructive lung disease include shortness of breath, low energy, and tightness in the chest.
Shortness of breath is the main symptom of obstructive lung disease. At first, this may only occur with physical activity. However, as the disease progresses, it can occur at any time, including when a person is resting.
Other symptoms of obstructive lung disease include:
- tightness in the chest
- a chronic cough that may produce mucus
- a feeling of mucus in the back of the throat, especially first thing in the morning
- a loss of energy
- weight loss
- a blue tint to the lips or nail beds
- repeated respiratory infections
- swelling in the legs and feet
Symptoms and their severity will vary from person to person depending on how much the disease has advanced. They may also vary based on the specific condition that is responsible for the obstructive lung disease.
Causes and risk factors
According to the National Heart, Lung, and Blood Institute, the main risk factor for obstructive lung disease is smoking. Up to 75 percent of people who have COPD either smoke or used to smoke.
Exposure to other lung irritants through the environment can also cause obstructive lung disease.
Some other lung irritants include:
- excessive exposure to secondhand smoke
There is also a genetic component to obstructive lung diseases. People can develop all types of obstructive lung disease without ever having smoked or having had significant exposure to environmental irritants.
In some cases, scientists have firmly established the role of genetics in developing obstructive lung disease.
For example, some people have an alpha-1 antitrypsin deficiency. This deficiency is a common genetic risk factor for emphysema.
Cystic fibrosis also has a genetic basis. The biological parents of a person with cystic fibrosis both carry a mutation in a gene called CFTR.
A doctor will usually perform a pulmonary function test to help diagnose obstructive lung disease.
During this test, a person forcibly breathes air through a mouthpiece using several techniques. During each blowing technique, a machine records information on the volume of the air release and how much air moves through the lungs.
The doctor will also ask the person questions about their symptoms and overall health. This will include information on a person's medical history and their exposure to environmental irritants, such as smoke and pollution.
Diagnosis often involves physical exams and some imaging tests, such as a CT scan or an X-ray of the chest.
In some cases, a doctor may look at the lungs with a thin, flexible lighted camera called a bronchoscope. They will use this to check for damage and obstructions.
Treatment and remedies
The aim of treatment for obstructive lung disease is to open the airways.
Treatment for obstructive lung disease typically involves opening the airways.
Obstructive lung disease causes bronchospasms, which are spasms of the smooth muscles in the walls of the airways.
There are several medications available to treat these spasms that fall under the category of bronchodilators.
Examples of bronchodilators include:
- combined medications, such as Combivent Respimat
- formoterol (Foradil), which people use in combination with an inhaled corticosteroid
- tiotropium (Spiriva)
- albuterol (Proventil HFA, Ventolin HFA, AccuNeb, ProAir HFA)
- salmeterol (Serevent), which people use in combination with an inhaled corticosteroid
- ipratropium (Atrovent)
Since obstructive lung disease can also cause inflammation, there are medications that a doctor may prescribe to help treat the inflammation. Some examples include:
- Singulair (montelukast)
- Qvar (inhaled corticosteroid)
- Prednisone (oral corticosteroids)
- Flovent (inhaled corticosteroid)
- Advair (combination inhaled corticosteroid and long-acting bronchodilator)
In some severe cases, a person may require a lung transplant. Other people may need oxygen therapy.
Preventing obstructive lung disease is similar to preventing other lung infections. There are some precautionary steps that a person can take, including:
- quitting smoking
- avoiding secondhand smoke
- exercising regularly
- taking precautions around chemicals and fumes
The outlook for a person with obstructive lung disease varies based on what kind of obstructive lung disease they have and, for some types of obstructive lung disease, how severe it is.
A study paper that appeared in the International Journal of Chronic Obstructive Pulmonary Disease suggests that the more advanced a person's COPD is, the lower their life expectancy may be.
A person with cystic fibrosis also has a reduced life expectancy, but this has increased with modern medicine.
For a person with an obstructive lung disease to live as long and healthily as possible, it is crucial that they follow their doctor's care plan and follow a healthful lifestyle.