Emphysema is the enlargement and destruction of the alveoli, which are small sacs of lung tissue at the end of the terminal bronchioles (smallest air pipes). The alveoli are where gaseous exchange takes place. Emphysema is a serious long-term disorder that requires regular medical treatment and cannot be cured.
The lung becomes less elastic and this leads to the collapse of the bronchioles, obstructing airflow out of the alveoli. Because air becomes trapped in the alveoli, the lungs are unable to deflate fully, despite full exhalation. The next breath cannot bring in enough fresh air, because there already is air in the alveoli. Therefore, less fresh air enters the alveoli for sufficient exchange of gasses.
Destruction of the alveoli walls decreases the total number of capillaries available for gas exchange and even less gas can be exchanged. The breathing becomes inefficient and more effort and energy needs to be spent on normal breathing. The breathing rate increases, while the affected person loses weight because more energy and reserves are being used for breathing.
There are two types of emphysema sufferers:
- The so-called Pink Puffers, who are pink and puffing: they have normal oxygen and carbon dioxide levels in the blood, but are breathless. These people suffer mainly from emphysema, with little bronchitis.
- The Blue Bloaters, who are blue and bloated: they do not seem breathless, but have decreased oxygen and raised carbon dioxide levels. As a result, they have more blood cells (polycythaemia) to help carry more blood to the tissues. These people suffer predominantly from chronic bronchitis.
In some emphysema sufferers the obstruction can be reversed to some degree by medications that enlarge or dilate the airways (bronchodilators).