In Australia, chronic bronchitis and emphysema usually occur in people who have smoked or continue to smoke cigarettes, but they can be caused by environmental or genetic factors. Asthma commonly occurs in non-smokers as well as smokers. It is caused by a number of different factors including but not limited to the environment, allergy and genes.
A small number of people can get emphysema from an inherited protein deficiency called alpha-1-antitrypsin deficiency.
Chronic bronchitis is a constant swelling and irritation of the breathing tubes (bronchi and bronchioles) and results in increased sputum production, a thick liquid secreted from the respiratory tract.
This condition usually occurs as a result of infection and is often related to smoking. Chronic bronchitis is recognised or identified when sputum is produced on most days for at least three months, for two consecutive years.
Airway obstruction occurs in chronic bronchitis because the inflammation and excessive sputum production causes the inside of the breathing tubes to be narrower than usual. Frequent infections occur due to the increased sputum.
As the breathing tubes or airways become narrower, it is harder for air to move in and out of the lungs and breathlessness results.
Emphysema is a condition where the air sacs (alveoli) become enlarged and the walls between them break down causing larger air spaces.
If you suffer from emphysema, this video should help you to visualise how your lungs are working to overcome your narrowing bronchi and bronchioles. You will also be able to see how the loss of elasticity in your lungs may make it more difficult for you to breathe out. This will help you to better understand how COPD affects your lungs.
Alpha-1 antitrypsin deficiency
Alpha-1 antitrypsin deficiency is a genetic disorder and those with Alpha-1 antitrypsin deficiency are at greater risk of developing COPD.
Alpha-1 antitrypsin (AAT) is a substance normally present in the blood; its role is to protect the lungs from damage. Over the course of a lifetime, the delicate tissues of the lungs are exposed daily to a variety of inhaled materials, such as pollutants, germs, dust and cigarette smoke. AAT helps the body fight against the damage caused by these pollutants.
People with a deficiency of AAT have too low a level to protect their lungs from the damaging enzymes produced by the body in reaction to the pollutants. This puts them at greater risk of developing COPD. COPD occurring at an early age is an important clue to this inherited disorder.
Click here to learn more about Alpha-1 antitrypsin.