Emphysema occurs when the air sacs in your lungs are gradually destroyed, making you progressively more short of breath. Emphysema is one of several diseases known collectively as chronic obstructive pulmonary disease (COPD). Smoking is the leading cause of emphysema.

As it worsens, emphysema turns the spherical air sacs — clustered like bunches of grapes — into large, irregular pockets with gaping holes in their inner walls. This reduces the surface area of the lungs and, in turn, the amount of oxygen that reaches your bloodstream.

Emphysema also slowly destroys the elastic fibers that hold open the small airways leading to the air sacs. This allows these airways to collapse when you breathe out, so the air in your lungs can't escape. Treatment may slow the progression of emphysema, but it can't reverse the damage.

Shortness of breath is by far the most common of emphysema symptoms. Most people with emphysema first notice something's wrong when they become winded during a previously routine activity. This might be climbing stairs or mowing the lawn.

The shortness of breath in emphysema results from structural changes in the lungs. These occur over years in response to lung damage, usually from smoking:

1. The linings between air sacs are destroyed, creating air pockets in the lungs
2. Air is trapped in these air pockets and is difficult to breathe out
3. The lungs slowly enlarge, and breathing takes more effort
4. Wheezing
5. persistant cough
6. Chest tightness or pain

In people with emphysema, the muscles responsible for breathing have to work harder, and tire out sooner. The result is feeling breathless -- at first with activity -- and at rest in advanced emphysema.

Treating emphysema focuses on improving emphysema symptoms -- mainly shortness of breath. Some emphysema treatments can reduce the number of hospitalizations and help preserve lung function.

1. Stopping smoking
2. Medications
3. Exercise
4. Nutrition
5. Oxygen therapy
6. Pulmonary rehabilitation

Inhaled bronchodilators relax and open the airways. They may be short-acting (albuterol, ipratropium) or long-acting (formoterol, salmeterol, tiotropium, and aclidinum bromide). These medicines may be available as inhalers ("puffers") or as a solution. A nebulizer machine aerosolizes the bronchodilator solution, which is then breathed through a tube.