Chronic Obstructive Pulmonary Disease (COPD)

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    Marina Shkayeva

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    Morgan Pfiffner, Shyam Jayaraman
    Last Updated: January 22, 2025

    Chronic obstructive pulmonary disease (COPD) is a chronic disease of the lungs that involves airway damage and blockage that worsens over time. The progressively worsening airway blockage causes the main symptoms of COPD: difficulty breathing, cough, and mucus production. While the most common cause of COPD is smoking, other causes can include significant exposure to air pollutants, frequent respiratory infections, and untreated asthma. Standard COPD treatments include use of specific inhalers to relax and open up the airways.

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    15,439 participants in 15 trials and 12 meta-analyses

    What is COPD?

    Chronic obstructive pulmonary disease (COPD) is a chronic condition characterized by irreversible lung damage, which leads to symptoms like difficulty breathing and cough. It typically involves both emphysema, in which air sacs in the lungd lose elasticity, and chronic bronchitis, which is marked by airway inflammation and increased mucus production.

    What is the prevalence of COPD?

    What are the main signs and symptoms of COPD?

    The main signs and symptoms of chronic obstructive pulmonary disease (COPD) include shortness of breath, wheezing, chronic cough with mucus, and fatigue and potential additional symptoms such as frequent infections, a blue tint to lips or fingernails, unintentional weight loss, muscle weakness, osteoporosis, and increased cardiovascular disease risk. The severity of the disease influences the variation in symptoms experienced by different people.

    How is COPD diagnosed?

    Chronic obstructive pulmonary disease (COPD) is diagnosed when a person exhibits long-term breathing difficulties and cough, particularly if they have risk factors like smoking or pollution exposure. Healthcare providers use a combination of signs, symptoms, medical histories, and various tests to confirm the diagnosis.

    What are some of the main medical treatments for COPD?

    The main treatments for chronic obstructive pulmonary disease (COPD) include quitting smoking and using inhalers (specifically bronchodilators) to manage symptoms and prevent exacerbations. The choice and frequency of inhaler use depend on the person's symptom severity and exacerbation history.

    Have any supplements been studied for COPD?

    Few supplements have been studied for chronic obstructive pulmonary disease (COPD), and there is no strong evidence to support their effectiveness. Some examples of these supplements include beetroot juice, chlorella, honey, and black seed oil.

    Are any supplements effective for COPD?

    How could diet affect COPD?

    A diet with antioxidant-rich fruits and vegetables may lower the risk of developing chronic obstructive pulmonary disease (COPD), but its effectiveness in managing symptoms is uncertain. Maintaining a healthy diet is crucial for people with COPD because malnutrition can lead to worsened outcomes that include muscle wasting and reduced quality of life.

    Are any particular foods helpful for COPD?

    Are there any other treatments for COPD?

    Exercise is recommended to help manage symptoms and progression of chronic obstructive pulmonary disease (COPD), with an emphasis on maintaining a regular exercise program rather than a specific type of exercise.

    What causes COPD?

    Chronic obstructive pulmonary disease (COPD) is primarily caused by long-term exposure to lung irritants, and cigarette smoke is the leading cause in the U.S. Other contributing factors include inhaling various types of smoke, pollution, chemical fumes, and a genetic condition known as alpha-1 antitrypsin deficiency.

    How does environment affect COPD?

    Examine Database: Chronic Obstructive Pulmonary Disease (COPD)

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    Frequently asked questions

    What is COPD?

    Chronic obstructive pulmonary disease (COPD) is a chronic condition characterized by irreversible lung damage, which leads to symptoms like difficulty breathing and cough. It typically involves both emphysema, in which air sacs in the lungd lose elasticity, and chronic bronchitis, which is marked by airway inflammation and increased mucus production.

    COPD is a chronic condition which occurs due to irreversible damage to the lungs with common symptoms such as trouble breathing and cough.[1]

    Normal lungs have many small stretchy air sacs that inflate upon inhalation and deflate upon exhalation. With COPD, less air can enter the lungs because air sacs have damaged walls and are less stretchy (this is called emphysema); and the airway becomes inflamed triggering cough and more mucus production (this is called chronic bronchitis). Most people have a COPD with both emphysema and chronic bronchitis, with variable severity.[2]

    What is the prevalence of COPD?
    Quick answer:

    In the US, approximately 6% of the population is diagnosed with chronic obstructive pulmonary disease (COPD), and the prevalence increases to 9.6% among people agea 55 to 64 and to 12.5% for those 65 and older. Globally, approximately 250 million people live with COPD, which often coexists with other chronic conditions and significantly affects quality of life and healthcare costs.

    In the US, about 6% of the population has been diagnosed with COPD. The prevalence seems to increase with age, with 9.6% of those 55-64 and 12.5% of those 65 years and older reporting a COPD diagnosis.[8] Globally, there are about 250 million people living with COPD. Over time COPD significantly impairs quality of life and ability to perform daily functions. It is associated with high healthcare costs and relatively frequent hospitalizations.[4]

    Usually, persons with COPD have multiple other chronic conditions. For example, about 47% of persons with COPD report also having asthma, 44% report also having depression, and about 18% report having diabetes.[8]

    What are the main signs and symptoms of COPD?

    The main signs and symptoms of chronic obstructive pulmonary disease (COPD) include shortness of breath, wheezing, chronic cough with mucus, and fatigue and potential additional symptoms such as frequent infections, a blue tint to lips or fingernails, unintentional weight loss, muscle weakness, osteoporosis, and increased cardiovascular disease risk. The severity of the disease influences the variation in symptoms experienced by different people.

    Symptoms of COPD vary depending on the severity of the disease. The most common symptoms include shortness of breath and wheezing, chronic cough (often with mucus), and fatigue. COPD is often associated with frequent infections of the airways and sometimes with a blue tint of lips or fingernails (due to a lack of oxygen).[1] The systemic inflammation from COPD can also cause symptoms outside the lungs. This can manifest as unintentional weight loss, muscle weakness, osteoporosis, increased risk of cardiovascular disease.[3]

    How is COPD diagnosed?

    Chronic obstructive pulmonary disease (COPD) is diagnosed when a person exhibits long-term breathing difficulties and cough, particularly if they have risk factors like smoking or pollution exposure. Healthcare providers use a combination of signs, symptoms, medical histories, and various tests to confirm the diagnosis.

    COPD is initially suspected when people present with long-term difficulty breathing and cough along with a risk factor such as smoking or exposure to pollution.[1] Healthcare providers diagnose COPD based on signs and symptoms, personal and family medical histories, and also test results (lung tests, imaging and blood tests).[2] Talk to your healthcare provider if you think you have COPD; do not self-diagnose.

    What are some of the main medical treatments for COPD?

    The main treatments for chronic obstructive pulmonary disease (COPD) include quitting smoking and using inhalers (specifically bronchodilators) to manage symptoms and prevent exacerbations. The choice and frequency of inhaler use depend on the person's symptom severity and exacerbation history.

    After COPD is diagnosed, the mainstay of treatment includes stopping smoking (if currently smoking) and the use of inhalers (bronchodilators) to manage symptoms and prevent exacerbations. The types of inhalers and their frequency of use depends on the individual person’s severity of symptoms and number of exacerbations.[1]

    Have any supplements been studied for COPD?

    Few supplements have been studied for chronic obstructive pulmonary disease (COPD), and there is no strong evidence to support their effectiveness. Some examples of these supplements include beetroot juice, chlorella, honey, and black seed oil.

    Not many supplements have been studied for COPD, and there’s no strong evidence to support their efficacy. Beetroot juice, chlorella, honey, and black seed (black seed) oil are examples of supplements that have been studied for COPD.[4]

    Are any supplements effective for COPD?
    Quick answer:

    There is no strong evidence that dietary supplements significantly improve lung function in chronic obstructive pulmonary disease (COPD), although some small studies suggest that nitrate-rich beetroot juice may enhance physical function and black seed oil could provide modest benefits when added to standard therapy. Overall, the effectiveness of these supplements remains limited based on current research.

    Overall, there is no strong evidence that certain dietary supplements improve lung-function in COPD. Small clinical studies show that taking 80-140 milliliters of nitrate-rich beet-root juice for 1-2 weeks, 300 milligrams of chlorella extract daily for 8 weeks, or 20 milligrams of Tualang honey daily for 6 months does not improve lung function or measures in people with COPD.[4] Although beetroot juice does not seem to improve lung function in COPD, it may improve physical function. Two small clinical studies in adults with COPD show that drinking 140 milliliters of nitrate-rich beetroot juice daily for 2 weeks, or twice weekly for 8 weeks, increases the total distance walked on the incremental shuttle walk test (ISWT) when compared to no intervention.[9][10]

    One small clinical study conducted in Egypt suggests that adding black seed (or black-seed) oil to standard therapy (corticosteroids and bronchodilator inhalers) might have modest benefits in COPD, possibly due to black seed’s anti-inflammatory and antioxidant effects. Adults with COPD who took 1 gram of black seed oil (containing at least 0.95% thymoquinone) capsules two times daily for 3 months had modestly increased expiratory flow compared to those receiving standard treatment only.[11][4]

    How could diet affect COPD?

    A diet with antioxidant-rich fruits and vegetables may lower the risk of developing chronic obstructive pulmonary disease (COPD), but its effectiveness in managing symptoms is uncertain. Maintaining a healthy diet is crucial for people with COPD because malnutrition can lead to worsened outcomes that include muscle wasting and reduced quality of life.

    A diet high in antioxidant-rich fruit and vegetables has been associated with a lower risk of developing COPD, though it is unclear whether this diet will help to manage symptoms. COPD is associated with worsened outcomes in malnourished individuals, such as muscle wasting and reduced exercise capacity, which leads to worsened quality of life and increased mortality risk, so it is especially important to maintain a healthy diet in those with COPD.[4]

    Are any particular foods helpful for COPD?
    Quick answer:

    Diets high in antioxidants, fruits, and vegetables are associated with a reduced risk of chronic obstructive pulmonary disease (COPD), whereas those rich in red meat and processed foods increase risk. However, research on the effect of increasing fruit and vegetable intake or protein on lung function and physical performance in people with COPD has shown conflicting results.

    Observational research has found that diets high in antioxidants, fruits, vegetables, and nuts are associated with reduced risk of COPD. Whereas, diets rich in red meat, processed food, and high-sugar carbonated drinks are associated with a higher risk COPD.[4] However, prospective research on increasing antioxidants in the diet has shown conflicting results. One small study in adults with stable COPD shows that increasing consumption of fruits and vegetables by at least 1 portion daily for 3 years seems to modestly improve lung function when compared to no dietary restriction.[12] In contrast, another small study in adults with moderate/severe COPD shows that consuming 5 or more portions of fruits or vegetables daily for 3 months does not seem to affect lung function when compared to consuming 2 portions or less.[13]

    There are conflicting reports whether increasing protein improves physical function in COPD. In a small clinical study in older adults (average age of 77 years) with COPD, drinking a nutritional drink (containing 10 grams of whey peptide, along with 5.6 grams of omega-3 fatty acids and antioxidant vitamins and minerals) in addition to mild exercise daily for 12 weeks improved the quadriceps muscle strength and performance on the 6-minute walk test (6MWT) when compared to engaging in exercise without supplementation.[14] However, two small studies in older adults with COPD (average age of 68-69 years), show that in addition to exercise, consuming either 9.3 grams of protein daily for 9 weeks or 19 grams of protein with 49 grams of carbohydrate daily for 8 weeks does not seem to further improve walking or muscle strength when compared to exercise alone.[15][16]

    Are there any other treatments for COPD?

    Exercise is recommended to help manage symptoms and progression of chronic obstructive pulmonary disease (COPD), with an emphasis on maintaining a regular exercise program rather than a specific type of exercise.

    Exercise is typically recommended to better manage COPD symptoms and progression. It seems that the type of exercise doesn’t matter as much as sticking to a regular exercise program.[5][6]

    What causes COPD?

    Chronic obstructive pulmonary disease (COPD) is primarily caused by long-term exposure to lung irritants, and cigarette smoke is the leading cause in the U.S. Other contributing factors include inhaling various types of smoke, pollution, chemical fumes, and a genetic condition known as alpha-1 antitrypsin deficiency.

    COPD is usually caused by long-term exposure to irritants that damage your lungs and airways. In the US, cigarette smoke is the main cause. Inhaling other types of smoke (pipe, cigar, biomass fuel, etc), pollution, and chemical fumes can also cause COPD. Also, some people have a genetic condition called alpha-1 antitrypsin deficiency which makes them more likely to sustain lung damage from pollution and smoke and sometimes lead to early-onset COPD.[7]

    How does environment affect COPD?
    Quick answer:

    Indoor air pollution from biomass fuel, commonly used in lower-income areas, is a significant cause of chronic obstructive pulmonary disease (COPD) due to the harmful smoke it produces. Additionally, occupational exposures to toxic gases and dust from various industries, particularly livestock farming, are also associated with the development of COPD.

    Indoor air pollution, especially involving exposure to smoke from biomass fuel, has been determined to be a cause of COPD. Biomass fuel includes burning wood, charcoal, vegetable matter, and animal excrement for energy. Biomass fuel is frequently used in lower-income countries and in poorer areas of developed countries to cook food. Biomass fuel has inefficient combustion and produces smoke that consists of nitrogen dioxide, carbon monoxide, sulfur dioxide, formaldehyde, and other pollutants and carcinogens.[17]

    Other airborne pollutants associated with COPD include occupational toxic gasses, grain dust in farms, and factory dust and fumes. Specific occupational exposures associated with COPD include coal and rock mining, transportation and trucking, beauty care (e.g. nail salon), as well as manufacture of plastic, textile, rubber, concrete, and leather. Farming with livestock (chicken, cows, etc.) seems to have a stronger association with COPD than crop farming. This may be because livestock farming increases exposures to ammonia, hydrogen sulfide, and various organic and inorganic dust.[17]

    Examine Database References

    1. Weight - Fuld JP, Kilduff LP, Neder JA, Pitsiladis Y, Lean ME, Ward SA, Cotton MMCreatine supplementation during pulmonary rehabilitation in chronic obstructive pulmonary diseaseThorax.(2005 Jul)
    2. Weight - Deacon SJ, Vincent EE, Greenhaff PL, Fox J, Steiner MC, Singh SJ, Morgan MDRandomized controlled trial of dietary creatine as an adjunct therapy to physical training in chronic obstructive pulmonary diseaseAm J Respir Crit Care Med.(2008 Aug 1)
    3. COPD Symptoms - Faager G, Söderlund K, Sköld CM, Rundgren S, Tollbäck A, Jakobsson PCreatine supplementation and physical training in patients with COPD: a double blind, placebo-controlled studyInt J Chron Obstruct Pulmon Dis.(2006)
    4. Exercise Capacity (with Heart Conditions) - Al-Ghimlas F, Todd DCCreatine supplementation for patients with COPD receiving pulmonary rehabilitation: a systematic review and meta-analysisRespirology.(2010 Jul)
    5. Weight - Funamoto M, Sunagawa Y, Katanasaka Y, Miyazaki Y, Imaizumi A, Kakeya H, Yamakage H, Satoh-Asahara N, Komiyama M, Wada H, Hasegawa K, Morimoto THighly absorptive curcumin reduces serum atherosclerotic low-density lipoprotein levels in patients with mild COPDInt J Chron Obstruct Pulmon Dis.(2016 Aug 26)
    6. Weight - A Borghi-Silva, V Baldissera, L M M Sampaio, V A Pires-DiLorenzo, M Jamami, A Demonte, J S Marchini, D CostaL-carnitine as an ergogenic aid for patients with chronic obstructive pulmonary disease submitted to whole-body and respiratory muscle training programsBraz J Med Biol Res.(2006 Apr)
    7. COPD Symptoms - Decramer M, Rutten-van Mölken M, Dekhuijzen PN, Troosters T, van Herwaarden C, Pellegrino R, van Schayck CP, Olivieri D, Del Donno M, De Backer W, Lankhorst I, Ardia AEffects of N-acetylcysteine on outcomes in chronic obstructive pulmonary disease (Bronchitis Randomized on NAC Cost-Utility Study, BRONCUS): a randomised placebo-controlled trialLancet.(2005 Apr 30-May 6)
    8. COPD Symptoms - De Benedetto F, Aceto A, Dragani B, Spacone A, Formisano S, Pela R, Donner CF, Sanguinetti CMLong-term oral n-acetylcysteine reduces exhaled hydrogen peroxide in stable COPDPulm Pharmacol Ther.(2005)
    9. COPD Symptoms - Peter N Black, Althea Morgan-Day, Tracey E McMillan, Phillippa J Poole and Robert P YoungRandomised, controlled trial of N-acetylcysteine for treatment of acute exacerbations of chronic obstructive pulmonary diseasePulmonary Medicine.()
    10. COPD Symptoms - Jiang C, Zou J, Lv Q, Yang YSystematic review and meta-analysis of the efficacy of N-acetylcysteine in the treatment of acute exacerbation of chronic obstructive pulmonary disease.Ann Palliat Med.(2021-Jun)
    11. COPD Symptoms - Huang C, Kuo S, Lin L, Yang YThe efficacy of -acetylcysteine in chronic obstructive pulmonary disease patients: a meta-analysis.Ther Adv Respir Dis.(2023)
    12. Neutrophil Activity - van Overveld FJ, Vermeire PA, De Backer WAInduced sputum of patients with chronic obstructive pulmonary disease (COPD) contains adhesion-promoting, therapy-sensitive factorsInflamm Res.(2000 Jan)
    13. Bronchitis Symptoms - Wei J, Pang CS, Han J, Yan HEffect of Orally Administered N-Acetylcysteine on Chronic Bronchitis: A Meta-analysis.Adv Ther.(2019-Dec)
    14. COPD Symptoms - Liang R, Liu D, Li H, Yan Y, Xie W, Zhai ZThe efficacy and safety of herbal formulas for adults with pulmonary hypertension combined with chronic obstructive pulmonary disease: a systematic review and meta-analysis involving 1,865 participants.J Thorac Dis.(2024 Sep 30)
    15. Blood Pressure - Alshafie S, El-Helw GO, Fayoud AM, Elrashedy AA, Gbreel MI, Alfayoumi SS, Mohamed IM, Abdelwadoud GT, Isa AS, Ragab KM, Nourelden AZEfficacy of dietary nitrate-rich beetroot juice supplementation in patients with chronic obstructive pulmonary disease (COPD): A systematic review and meta-analysis.Clin Nutr ESPEN.(2021 Apr)
    16. Blood Pressure - Yang H, He S, Chen F, Liang L, Pan JEfficacy and safety of nitrate supplementation on exercise tolerance in chronic obstructive pulmonary disease: A systematic review and meta-analysis.Medicine (Baltimore).(2022 Jan 14)
    17. Exercise Capacity - Wang J, Feng F, Zhao Y, Bai L, Xu Y, Wei Y, He H, Zhou XDietary nitrate supplementation to enhance exercise capacity in patients with COPD: Evidence from a meta-analysis of randomized controlled trials and a network pharmacological analysis.Respir Med.(2024-Feb)
    18. Vascular Function - Delacoste FBC, Goulart CDL, Guidoti AB, Türck P, Eibel B, Irigoyen MC, de Araujo CLP, Dal Lago PEvaluating the impact of short-term nitrate-rich dietary supplementation on endothelial function in COPD: A randomized crossover study.Respir Med.(2024 Oct)
    19. Uric Acid - Abdollahi S, Vajdi M, Meshkini F, Vasmehjani AA, Sangsefidi ZS, Clark CCT, Soltani SResveratrol may mildly improve renal function in the general adult population: A systematic review and meta-analysis of randomized controlled clinical trials.Nutr Res.(2023-May)
    20. C-Reactive Protein (CRP) - Armita Mahdavi Gorabi, Saeed Aslani, Danyal Imani, Bahman Razi, Thozhukat Sathyapalan, Amirhossein SahebkarEffect of resveratrol on C-reactive protein: An updated meta-analysis of randomized controlled trialsPhytother Res.(2021 Dec)
    21. Exercise Capacity (with Heart Conditions) - Marwood S, Jack S, Patel M, Walker P, Bowtell J, Calverley PNo effect of glutamine ingestion on indices of oxidative metabolism in stable COPDRespir Physiol Neurobiol.(2011 Jun 30)
    22. Lung Function - Pletcher MJ, Vittinghoff E, Kalhan R, Richman J, Safford M, Sidney S, Lin F, Kertesz SAssociation between marijuana exposure and pulmonary function over 20 yearsJAMA.(2012 Jan 11)
    23. Lung Function - Yu H, Lei T, Su X, Zhang L, Feng Z, Dong M, Hou Z, Guo H, Liu JEfficacy and safety of three species of L. in patients with chronic obstructive pulmonary disease: A systematic review and meta-analysis.Front Pharmacol.(2023)
    24. C-Reactive Protein (CRP) - Yu H, Su X, Lei T, Zhang C, Zhang M, Wang Y, Zhu L, Liu JEffect of Omega-3 Fatty Acids on Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.Int J Chron Obstruct Pulmon Dis.(2021 Sep 23)
    25. Exercise Tolerance - Kikuchi H, Shiozawa N, Takata S, Ashida K, Mitsunobu FEffect of repeated Waon therapy on exercise tolerance and pulmonary function in patients with chronic obstructive pulmonary disease: a pilot controlled clinical trial.Int J Chron Obstruct Pulmon Dis.(2014)
    26. Cathelicidin - Sanders EC, Burkes RM, Mock JR, Brown TT, Wise RA, Hansel NN, Liu MC, Drummond MBBronchoalveolar Lavage and Plasma Cathelicidin Response to 25-Hydroxy Vitamin D Supplementation: A Pilot Study.Chronic Obstr Pulm Dis.(2021-Jul-28)
    27. Interleukin 8 - Norheim KL, Ben Ezra M, Heckenbach I, Andreasson LM, Eriksen LL, Dyhre-Petersen N, Damgaard MV, Berglind M, Pricolo L, Sampson D, Dellinger RW, Sverrild A, Treebak JT, Ditlev SB, Porsbjerg C, Scheibye-Knudsen MEffect of nicotinamide riboside on airway inflammation in COPD: a randomized, placebo-controlled trial.Nat Aging.(2024 Dec)
    Chronic Obstructive Pulmonary Disease (COPD): Symptoms, causes, treatments, and your questions answered.