Emphysema is a chronic respiratory disorder characterized by the gradual damage and destruction of the alveoli (air sacs) in the lungs. This damage causes the air sacs to lose their elasticity and eventually rupture, creating larger, less efficient air spaces. This reduces the surface area available for gas exchange, leading to shortness of breath and reduced oxygen intake. Two causes of emphysema are: • Long-term exposure to airborne irritants, such as tobacco smoke (the most common cause). • Exposure to air pollution and chemical fumes.