COPD (chronic obstructive pulmonary disease) is a common disorder, affecting an estimated 8 percent of the world's population and 10 percent of people over the age of 40. In 2004, COPD was the fourth leading cause of death in the U.S.

What exactly is COPD? This condition results from inflammation in the lungs caused by inhalation of noxious or toxic particles or gases. It limits the amount of air that can be inhaled into the lungs, and the air that is inhaled cannot then be exhaled fully. The condition is usually progressive and is not fully reversible with treatment.

Viral infections, like the flu, and environmental factors, such as dust and pollen, can trigger symptoms, which typically include a chronic, phlegm (sputum)-producing morning cough, sometimes accompanied by wheezing. As the disease progresses, people have episodes of more severe cough, thickened sputum, and increased wheezing and shortness of breath, all of which will often prompt the first visit to the doctor.

Over time, people with COPD, usually in their 60s and 70s, note worsening fatigue and weakness accompanied by severe shortness of breath that makes it difficult to walk or climb stairs. The lung damage frequently causes heart failure with swelling of the legs.

Smoking is the most common factor in the development of COPD, although about a quarter of patients with COPD have never smoked. Nonetheless, the most important measure for both prevention and treatment of COPD is to stop smoking and to avoid passive smoke.

Even if a person has had COPD for years, studies have shown that its progression is slowed when patients stop smoking.

Treatments include inhaled bronchodilators to keep airways open and decrease secretions; administration of steroids to reduce inflammation, either by inhalation or by mouth; and prompt antibiotic treatment of bacterial pulmonary infections such as bronchitis or early pneumonia. A pneumonia vaccine and an annual flu shot are essential to lessen the risk of infections.

About a third of people with COPD suffer from significant malnutrition because of diminished appetite and the need to expend so much energy to overcome the difficulties in breathing.

These patients should consider eating small, frequent meals with nutrient-dense foods. Treatment with supplemental oxygen can improve shortness of breath and may prolong life.