COPD An Overview of Chronic Lower Respiratory Disease (CLRD) By Mark Stibich, PhD Updated on July 31, 2023 Medically reviewed by Sanja Jelic, MD Print Table of Contents View All Table of Contents Causes Symptoms Diagnosis Treatment A Word From Verywell Chronic lower respiratory disease (CLRD) is a group of disorders affecting the lungs and airways and is considered the fourth-leading cause of death in the United States. CLRD encompasses four commonly overlapping chronic diseases: chronic obstructive pulmonary disease (COPD), asthma, emphysema, and chronic bronchitis. This article looks at the causes and symptoms of CLRD as well as how this group of conditions is diagnosed and treated. Erik Jonsson / EyeEm / Getty Images Causes Cigarette smoking is the major cause of these illnesses, accounting for about 80% 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). Symptoms 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 breathWheezingIncreased mucus (sputum) productionChronic coughRacing heartbeatFatigue Additional symptoms may vary depending on the root condition: Chronic obstructive pulmonary disease: 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. Emphysema: In 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. 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. Diagnosis 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: Blood tests such as arterial blood gases (ABG) and a complete blood count (CBC) Lung function tests such as peak expiratory flow rate (PEFR) and spirometry Imaging such as chest X-rays, which are often used to support a diagnosis and may show inflammation in airways Pulse oximetry Exercise capacity Treatment 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 or wheezing 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. How Chronic Obstructive Pulmonary Disease (COPD) Is Treated 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. 3 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. Centers for Disease Control and Prevention. Chronic obstructive pulmonary disease (COPD) includes: chronic bronchitis and emphysema. Centers for Disease Control and Prevention. Chronic obstructive pulmonary disease (COPD). Demeyer H, Donaire-Gonzalez D, Pons IS, Anto JM, Garcia-Aymerich J. The importance of being physically active on functional decline in patients with COPD. Eur Respir J. 2016;48(suppl 60). doi:10.1183/13993003.congress-2016.OA1522 Additional Reading Demeyer H, Donaire-Gonzalez D, Pons IS, Anto JM, Garcia-Aymerich J. The importance of being physically active on functional decline in patients with COPD. European Respiratory Journal, 2016 48: OA1522. doi:10.1183/13993003.congress-2016.OA1522 By Mark Stibich, PhD Mark Stibich, PhD, FIDSA, is a behavior change expert with experience helping individuals make lasting lifestyle improvements. See Our Editorial Process Meet Our Medical Expert Board Share Feedback Was this page helpful? Thanks for your feedback! What is your feedback? Other Helpful Report an Error Submit