Emphysema, or 'lung rot', is a degenerative disease of the lung tissue. It destroys the tiny air sacs in the lungs slowly over many years. The lungs cannot repair this damage. Emphysema is an irreversible disease.

The main symptom of emphysema is a feeling of breathlessness that gradually becomes more severe over the years. Sufferers often say they feel like they're suffocating. Almost all smokers will get emphysema. The damage to the lungs occurs for many years before the effects are felt.

Almost 4,200 Australians die from emphysema caused by smoking every year, while emphysema accounts for around one-quarter of all deaths caused by smoking.