You could be a politician or you could have emphysema. The disorder usually is due to years of irritation from cigarette smoke, but anyone could get emphysema if exposed to years of air pollution or exposure to industrial dust [1p887].
The long-term irritation and resulting inflammation damages or destroys the walls of air sacs in the lungs [2]. The loss of elasticity causes bronchioles to collapse and air becomes trapped in the air sacs, over-stretching them and not allowing full ability to exhale [2]. The air sacs can rupture and the lung is left with abnormally large air spaces that stay filled with air [2].
Oxygen diffusion across the respiratory membrane is also reduced due to less surface area for gas exchange [1p887]. This limits the amount of oxygen in the blood and can result in leaving a person breathless even during mild exercise [1p887]. Symptoms are coughing, loss of appetite as well as fatigue [2].
Excessive mucus and inactivity of cilia–eventually allow irritants to damage the alveolar tissue, which can end up allowing squamous cancer cells to spread into the lower respiratory tract [3].
It's worth noting that oxygen therapy is one of the few therapies actually proven to keep those with emphysema living longer and with a better quality of life [4]. If you know anyone with emphysema, let them know. Oxygen therapy at night can be especially beneficial [4]. And if the patient doesn't exercise, all the more reason.
Three out of four adults with alpha-1 antitrypsin deficiency (AAT), a genetic disorder, will also get emphysema. Since the liver makes the protein and releases it into the blood stream it only takes a blood test to find out if you have AAT deficiency.
References
1. Tortora, GJ, Derrickson, B. Principles of Anatomy and Physiology, 11th ed; 2006. New York: John Wiley & Sons.
2. Mayo Foundation for Medical Education and Research. Emphysema and Smoking. Available at http://emphysema.org/.
3. http://www.pul.unimaas.nl/respir.htm
4. http://www.nslij.com/body.cfm?id=5987
5. http://www.nlm.nih.gov/medlineplus/alpha1antitrypsindeficiency.html
