References:

1. Cleveland Clinic. Chronic Obstructive Pulmonary Disease (COPD). Available from: https://my.clevelandclinic.org/health/diseases/8709-chronic-obstructive-pulmonary-disease-copd Accessed on 25 February 2025.
2. Emphysema. Available at https://my.clevelandclinic.org/health/diseases/9370-emphysema. Accessed on 25 February 2025.
3. American Lung Association. Early warning signs of COPD. www.lung.org. 2023. Available from: https://www.lung.org/lung-health-diseases/lung-disease-lookup/copd/symptoms-diagnosis/early-warning-signs Accessed on25 February 2025.
4. Mayo Clinic. COPD. Available from: https://www.mayoclinic.org/diseases-conditions/copd/symptoms-causes/syc-20353679 Accessed on 25 February 2025.
5. Mayo Clinic. COPD – Diagnosis and Treatment. Available from: https://www.mayoclinic.org/diseases-conditions/copd/diagnosis-treatment/drc-20353685. Accessed on 25 February 2025.
6. American Lung Association. Early warning signs of COPD. www.lung.org. 2023. Available from: https://www.lung.org/lung-health-diseases/lung-disease-lookup/copd/symptoms-diagnosis/early-warning-signs Accessed on 25 February 2025.
7. 6 tips for living with COPD. Available from: https://www.mayoclinichealthsystem.org/hometown-health/speaking-of-health/6-tips-for-living-with-copd Accessed on 18 October 2024.
8. 6 tips for living with COPD. Available from: https://www.mayoclinichealthsystem.org/hometown-health/speaking-of-health/6-tips-for-living-with-copd Accessed on 18 October 2024.
9. Uptodate. Chronic obstructive pulmonary disease (COPD) (The Basics).  Available  from:  https://www.uptodate.com/contents/chronic-obstructive-pulmonary-disease-copd-the-basics?topicRef=4647&source=see_link