Chronic Obstructive Pulmonary Disease: Risks and Symptoms
Chronic obstructive pulmonary disease (COPD) is a long-term lung condition that causes constant respiratory symptoms and airflow limitation. It commonly develops after prolonged exposure to harmful particles or gases, with tobacco smoke and household or outdoor air pollution being important risk factors. COPD can affect breathing, physical activity and quality of life. However, its course and severity vary considerably between individuals. According to a 2026 systematic review of 23 studies and over 27,000 adults, the pooled spirometry-confirmed COPD prevalence is 13% [1]. COPD is not simply a disease of older smokers. Exposure to household air pollution, occupational dusts and fumes, outdoor air pollution and certain genetic conditions can also contribute to COPD risk.
This article explains COPD symptoms, causes, risk factors, complications, diagnosis and treatment options, including the role of pulmonary rehabilitation.
Highlights
- COPD is a distinct chronic lung disease. It causes respiratory symptoms and airflow limitation.
- Smoking is not the only risk factor for COPD. Household air pollution, occupational exposures, outdoor pollution and genetic factors can also contribute.
- Asthma and COPD can share symptoms but are different, and some people may have features of both, but poorly controlled asthma does not simply “turn into” COPD.
- Pulmonary rehabilitation can improve exercise capacity, breathlessness and quality of life; it is not primarily a treatment that increases lung capacity.
What Is COPD?
COPD is a chronic respiratory disease characterised by constant respiratory symptoms and airflow obstruction that is not fully reversible.
Here are the most common symptoms of COPD:
- Breathlessness
- Chronic cough
- Sputum production (thick mixture of mucus and saliva)
- Wheezing
- Reduced exercise tolerance
- Fatigue
Symptoms and airflow limitation can vary substantially from one person to another. COPD is usually diagnosed using spirometry, together with the person’s symptoms, exposure history and clinical assessment.
Types for Chronic Obstructive Pulmonary Disease (COPD)
Some of the major reasons for disease exacerbation include tobacco use and exposure to harmful pollutants.
COPD patients suffer from two common types, which include emphysema and chronic bronchitis; however, both conditions can coexist among patients.
1. Emphysema
Emphysema is a condition where the alveoli, which are commonly referred to as the walls of the air sacs, are damaged. As a result, the alveoli lose their shape and ability to recoil properly during the expiratory phase of normal breathing. Air trapped within damaged alveoli continues to affect the overall respiratory phase, ultimately disrupting the cycle of airway obstruction. This prolonged air trapping leads to lung hyperinflation, which reduces gas-exchange efficiency. Furthermore, it makes breathing difficult and impairs blood oxygenation, leading to carbon dioxide accumulation in the blood.
2. Chronic Bronchitis
Chronic bronchitis is a subtype of COPD characterised by inflammation in the large airways. This inflammation also narrows the airways and increases mucus buildup, leading to cough, a common symptom of chronic bronchitis.
In India, recent research suggests that chronic bronchitis is common among individuals aged 35 years and older. It also suggests a higher prevalence among men (4.29%) than among women (2.7%) [2].
Understanding chronic obstructive pulmonary disease symptoms is critical for early detection and recognition to improve COPD treatment outcomes.
COPD and Asthma: The Differences
Asthma and COPD can both cause cough, wheezing and breathlessness, but they are different conditions.
| Feature | Asthma | COPD |
| Symptom Pattern | Variable (fluctuates over time) | Ongoing or progressive |
| Airflow Limitation | Variable expiratory restriction | Fixed or minimally reversible |
| Primary Site / Pathology | Airway inflammation and bronchospasm | Abnormalities in airways and/or alveoli |
| Primary Causes / Triggers | Allergens, infections, exercise, cold air, smoke | Long-term exposure to harmful particles or gases |
Signs and Symptoms for COPD
COPD symptoms often develop gradually, so some people may not recognise the significance of changes in their breathing.
1. Breathlessness
Shortness of breath may initially occur during activities such as climbing stairs or walking quickly. As the disease progresses, breathlessness may occur with less demanding activities. However, breathlessness has many possible causes and does not automatically indicate COPD.
2. Constant Cough
A long-lasting cough can occur in COPD, particularly in people with chronic bronchitis. It can also result from asthma, infections, post-nasal symptoms, smoking and other conditions.
3. Sputum Production
Some people with COPD produce mucus regularly. Changes in the amount, colour or consistency of sputum can sometimes accompany respiratory infections or sudden worsening of symptoms and may require medical assessment.
4. Wheezing
Wheezing is a whistling sound produced by narrowed airways. It can occur in COPD but is also common in asthma and several other respiratory conditions.
5. Reduced Exercise Tolerance
People with COPD may find that activities they previously performed easily now cause breathlessness or fatigue. Reduced exercise tolerance can result from several factors, including airflow limitation, muscle deconditioning and other health conditions.
Major Causes for COPD
COPD develops from prolonged exposure to lung irritants or genetic factors:
- Tobacco Smoke: Primary risk factor; long-term active smoking or secondhand exposure causes severe airway and tissue damage.
- Household Air Pollution: Frequent exposure to smoke from burning biomass fuels (wood, crop residues, animal dung) in unventilated cooking areas. Biomass fuel exposure has been shown to correlate with lower forced expiratory volume in one second (FEV1) percentages, with 61% affected [3].
- Outdoor Air Pollution: Chronic exposure to vehicular exhaust, industrial emissions, particulate matter, and nitrogen dioxide.
- Occupational Hazards: Extended workplace exposure to chemical fumes, industrial dust, agricultural debris, construction particles, or mining materials.
- Genetics: Rare inherited conditions, primarily alpha-1 antitrypsin deficiency, which can trigger early-onset emphysema.
COPD Complications
COPD can affect more than the lungs, particularly when disease is advanced or poorly controlled.
The possible complications are as follows:
Respiratory Infections
People with COPD may experience respiratory infections and exacerbations. An infection can temporarily worsen breathlessness, coughing and sputum production.
Respiratory Failure
Advanced COPD can impair the lungs’ ability to maintain appropriate oxygen and carbon dioxide levels. Respiratory failure can be acute or chronic and requires medical assessment.
Pulmonary Hypertension
Some people with advanced COPD develop pulmonary hypertension. Long-term abnormalities in the lungs and blood vessels can increase pressure in the pulmonary circulation and strain the right side of the heart.
Cardiovascular Disease
COPD is associated with increased cardiovascular risk. People with COPD may therefore require assessment and management of other cardiovascular risk factors where appropriate.
Hypoxemia and Hypercapnia
Hypoxemia means a lower-than-normal level of oxygen in the blood. Hypercapnia means an elevated level of carbon dioxide in the blood. These abnormalities can occur in advanced COPD and during certain exacerbations, but they are not present in every person with COPD.
How Is COPD Diagnosed?
Do not base a COPD diagnosis only on symptoms such as cough or breathlessness. The Spirometry Test is central to confirming persistent airflow obstruction. It measures parameters such as:
- Forced expiratory volume in one second (FEV1)
- Forced vital capacity (FVC)
- FEV1/FVC ratio
A clinician interprets the results alongside symptoms and exposure history. Depending on the clinical situation, doctors may also consider:
- Chest X-ray
- CT scan
- Oxygen saturation measurement
- Blood tests
- Blood gas analysis
- Alpha-1 antitrypsin testing
- Exercise assessment
Not every person with suspected COPD requires every test.
Also read: Winter Asthma Triggers and How to Avoid Them
Final Thoughts
COPD is a chronic lung disease characterised by persistent respiratory symptoms and airflow limitation. Smoking is an important risk factor, but COPD can also develop in people exposed to household air pollution, occupational hazards, outdoor pollution or certain genetic conditions.
Asthma and COPD are different diseases, although some people may have features of both. Chronic bronchitis is a clinical term that can occur alongside COPD but should not be treated as simply another name for the disease. Our NABH-accredited Eskag Sanjeevani Hospitals provide respiratory evaluation and treatment services for patients with COPD and other lung conditions. If you have a severe cough, breathlessness, wheezing, or reduced exercise tolerance, a medical assessment can help determine the cause and whether lung-function testing is appropriate.
References
- Halder P, Khaiwal R, Goel S, Kumar N, Sarkar M, Soni M, Nongkynrih B, Prabhakar MC, Mamgai A, Rathor S. Burden of chronic obstructive pulmonary disease among Indian adults: systematic review and meta‑analysis. BMC Pulm Med. 2026 Feb 7;26(1):112. doi: 10.1186/s12890-026-04134-0.
- Panigrahi, A. and Padhi, B.K. (2018). Chronic bronchitis and airflow obstruction is associated with household cooking fuel use among never-smoking women: A community-based cross-sectional study in Odisha, India. BMC Public Health, 18(1). doi:10.1186/s12889-018-5846-2.
- Pandey AK, Verma AK, Singh A, Kant S, Chaudhary SC, Bajpai J, Dixit RK. The severity of non-smoking chronic obstructive pulmonary disease is correlated with biomass fuel exposure and COPD assessment test score. Lung India. 2024 Jul 1;41(4):251-258. doi: 10.4103/lungindia.lungindia_304_23.
COPD is mainly caused due to prolonged exposure to pollutants and irritants that damage the lung function. Smoking is a primary cause, and other secondary causes include pollution, exposure to harmful fumes in commercial places, and genetic factors.
Early signs and symptoms of COPD include chronic cough with high levels of mucus and shortness of breath during physical exertion. Other signs include fatigue and chronic respiratory infections.
Yes, COPD is much more harmful compared to asthma due to its progressive nature. Asthma, on the other hand, is episodic in nature and is usually manageable. Symptoms are similar for both conditions; however, poorly controlled asthma leads to symptoms of COPD.
Smokers are at a high risk of developing COPD, which can cause severe health implications over time. Moreover, people with a deficiency of alpha-1-antitrypsin are also at risk of COPD.
Yes, second-hand smoke is a critical factor for developing COPD among non-smokers. Some of the other factors include indoor and outdoor air pollution and dust exposures.