Emphysema is a lung condition that makes you short of breath and causes a persistent cough. It is usually caused by smoking.
Emphysema happens when the air sacs (alveoli) in your lungs get damaged and are eventually destroyed. This makes it hard to absorb enough oxygen when you breathe. It is one of the lung diseases grouped together as COPD (chronic obstructive pulmonary disease). To find out more about the causes, symptoms, diagnoses and treatment of emphysema, see COPD.