Emphysema is a chronic condition affecting the lungs. Individuals with emphysema gradually lose the natural elasticity of the lung's air sacs, which causes difficulty breathing and often painful or uncomfortable respiration. As the elasticity is lost, small holes begin to form in the lung tissue and the air sacs become damaged. Over time, emphysema leads to Chronic Obstructive Pulmonary Disease (COPD), which in turn affects the heart.

Emphysema is a gradual and progressive condition that stems from years of exposure to chemical pollutants, most often from cigarette smoking. In some cases emphysema is caused by workplace and environmental air pollutants, and in a very small percentage of people, emphysema is caused by an inherited chemical imbalance in the lung tissue. This rare, inherited condition is known as early onset emphysema or AAT deficiency-related emphysema.

Symptoms of emphysema include tightness in the chest, painful or difficult breathing, shortness of breath after mild exercise or exertion, and chronic cough, all caused by the progressive destruction of lung tissue and the air sacs. Often, emphysema is diagnosed in patients who have previously had chronic bronchitis, but are no longer responding to antibiotics. Emphysema makes it more difficult for the lungs to pass oxygen into the bloodstream. Over time, as the air sacs become further damaged, a person with emphysema may find that simply walking a short distance causes them to become short of breath.

Emphysema is an irreversible condition, but treatment exists to make living with the disease more comfortable. Treatment includes bronchodilators, prescription drugs that relax the airway, to relieve constricted airways and breathing exercises to strengthen the lungs. In severe cases, a lung transplant may be performed.

Emphysema affects more men than women, but almost always smokers or those who are regularly exposed to cigarette smoke. It is estimated that cigarette smoking is the cause of nearly 80% of all lung diseases, including emphysema. Quitting smoking will help slow the progression of emphysema.