Emphysema refers to a lung disease that is chronic, and is usually the result of long-term exposure to tobacco smoke or to other harmful chemicals. Tobacco smoke and other chemicals, when breathed into the lung, can destroy lung structures supporting the alveoli (primary areas of gas exchange in the lungs), as well as capillaries that feed the alveoli. Thus, emphysema causes a loss of elasticity of lung tissues, and results in the collapse of small airways in the lungs, and air being trapped.

The symptoms of emphysema include the following:

- Shortness of breath on exertion (such as running or climbing stairs) or for severe cases of emphysema, even at rest)
- A chronic, mild cough
- Hyperventilation (the need to breath faster or deeper than normal)
- Becoming easily fatigued
- After time, possible deformation of the hands and fingers

Typically, emphysema is diagnoses by a physician conducting tests after a patient has reported experiencing a shortness of breath when undergoing exertion. Typical tests include lung function testing, diffusion testing, chest X-rays and CT-scans, MRIs, blood tests and arterial blood gas sampling.

Although emphysema is currently not a reversible condition, there are treatments to help relieve the symptoms of emphysema. The most important treatment for slowing the progression of emphysema is that the patient stop smoking and attempt to avoid exposure to second-hand smoke as well. Other treatment options include supplemental oxygen to assist with breathing, a variety of medications that are being researched and tested, and even lung transplants. For those patients that require oxygen supplementation, a variety of portable oxygen systems are available to minimize discomfort and improve mobility.