An Overview of Chronic Lower Respiratory Disease (CLRD)

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Chronic lower respiratory disease (CLRD) is a group of conditions that affect the lungs and are considered the fourth-leading cause of death in the United States. CLRD encompasses chronic obstructive pulmonary disease (COPD)—which includes emphysema and chronic bronchitis—as well as asthma, pulmonary hypertension, and occupational lung diseases. The conditions are most common among smokers, but everyone should understand their risk.

Man smoking cigarette close up
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Cigarette smoking is the major cause of these illnesses, accounting for about 80 percent of cases. However, exposure to air pollutants in the home and workplace, genetic factors, and respiratory infections can also play a role in the development of chronic lower respiratory disease, according to the Centers for Disease Control and Prevention (CDC).


As mentioned, chronic lower respiratory disease is an umbrella term for diseases of the lungs. Typical symptoms across most of these conditions include:

  • Shortness of breath
  • Wheezing
  • Increased mucus (sputum) production
  • Chronic cough
  • Racing heartbeat
  • Fatigue

Additional symptoms may vary depending on the root condition:

  • Chronic obstructive pulmonary disease (COPD): COPD is characterized by a limitation of airflow into and out of the lungs. Symptoms include chronic cough, shortness of breath, phlegm production, and chest tightness.
  • EmphysemaIn people with emphysema—a type of COPD—some of the air sacs in the lungs are damaged. Symptoms include chronic cough, shortness of breath, phlegm production, frequent respiratory infections, chest pain, and cyanosis.
  • Chronic bronchitis: When the lining of the lungs' airways are red and swollen, that is one sign of chronic bronchitis, another type of COPD. Other symptoms include mild fever, runny nose, sore throat, chest and nasal congestion, and a productive cough that turns into a dry, wheezing cough.
  • Asthma: Asthmatic airways are highly sensitive to certain triggers (smoke, pollen, infections, etc.) and may be plagued by symptoms such as wheezing, coughing, shortness of breath, and chest tightness. Symptoms are not constant and may increase during asthmatic episodes.
  • Occupational lung diseases: Smoking, secondhand smoke, radon, air pollution, and on-the-job exposure to substances such as asbestos may result in symptoms varying in severity from recurrent respiratory infections to coughing up blood.


CLRDs are primarily diagnosed via a thorough physical exam, intake history, and an assessment of lung function, but each condition may require more specific testing in order to narrow down the diagnosis.

The primary tests used to diagnose most lower respiratory diseases include some combination of the following:


The severity of the illness and treatment vary based on the particular type of chronic respiratory disease. If you're a current smoker, the most important thing you can do to aid your treatment is to quit smoking. Avoiding secondhand smoke and other air pollutants may also help, as can wearing a mask or ventilator at your workplace if you're regularly around triggering substances.

Your healthcare provider will help you create a pulmonary rehabilitation program focused on your specific disease management needs and that works to help you boost your quality of life.

Certain symptoms, such as coughing, wheezing, or high blood pressure, may be treated with medications. In patients with low blood oxygen levels as a result of their chronic lower respiratory disease, supplemental oxygen may be given.

Exercise has also been shown to be helpful in many different lung conditions, as it helps improve lung function. One study of 114 COPD patients found that physical activity in the form of walking positively affected lung function decline.

A Word From Verywell

The optimal form of treatment and therapy for CLRDs will depend on your specific condition. But with all forms of CLRDs, there are many steps you can take to prevent further progression of the disease, most of which center on close monitoring, keeping up with medications, and following pulmonary rehabilitation techniques, in addition to maintaining balanced nutrition, good hydration, regular gentle exercise, and striving to reduce stress. Work together with your healthcare team to find an integrative treatment plan that works best for you.

2 Sources
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. Centers for Disease Control and Prevention. Chronic obstructive pulmonary disease (COPD) includes: chronic bronchitis and emphysema.

  2. Centers for Disease Control and Prevention. Chronic obstructive pulmonary disease (COPD).

Additional Reading

By Mark Stibich, PhD
Mark Stibich, PhD, FIDSA, is a behavior change expert with experience helping individuals make lasting lifestyle improvements.