Causes

Causes of emphysema

Emphysema is usually a result of cigarette smoking. Atmospheric pollution is sometimes a predisposing factor. It can also be a complication of the inherited condition known as alpha-1 antitrypsin deficiency.

Tobacco smoke and other air pollutants are believed to cause emphysema by provoking the release of chemicals within the alveoli that damage the alveolar walls. Alpha-1 antitrypsin is thought to protect against this chemical damage; hence, people with a deficiency of this substance are particularly at risk. The damage is slight at first, but in heavy smokers it becomes progressively worse, with the alveoli bursting and blending to form fewer, larger sacs with less surface area, and with consequent impairment of oxygen and carbon dioxide exchange. Over the years the lungs become less and less elastic, which further reduces their efficiency.

Eventually – sometimes are many years – the level of oxygen in the blood starts to fall, with either of two effects. In some cases pulmonary arterial hypertension (raised blood pressure in the pulmonary artery) develops leading to cor pulmonale (enlargement and strain on the right side of the heart) and, subsequently, edema (accumulation of fluid in the tissues), particularly in the lower legs. Other sufferers are able to compensate for oxygen deficiency to some extent by breathing faster. Why individuals react in one and not the other of these different ways is not known.

Referred to :

http://www.daviddarling.info/encyclopedia/E/emphysema.html