How to prevent chronic obstructive pulmonary disease (COPD)?

Lifestyle modifications that can help prevent COPD, or improve function in COPD patients, include: complete smoking cessation, avoiding respiratory irritants and infections, avoiding allergens, maintaining good nutrition, drinking lots of fluids, avoiding excessively low or high temperatures and very high altitudes, maintaining proper weight, and exercising to increase muscle tone.

Avoid smoking tobacco or exposure to secondhand tobacco smoke. Smoking is the leading cause of COPD. Although you cannot undo the damage that smoking has already caused, you can prevent further lung damage by quitting. Avoiding conditions that may irritate the lungs can reduce breathing problems in people with COPD. These conditions include indoor and outdoor air pollution; smog; cold, dry air; hot, humid air; or high altitudes. Avoiding respiratory illnesses, such as the flu (influenza) and pneumonia, can decrease the risk of your COPD worsening. Talk with your doctor about getting vaccinations against them.  

Use appropriate protective gear (e.g. face mask) in the workplace to avoid inhaling hazardous substances. Get plenty of physical activity for good lung health. If you already have COPD, avoid colds and flus, which can worsen the disease. Get annual flu and pneumococcal vaccinations to avoid such infections. 

Smoking cessation is the most important thing you can do to prevent or slow damage to your lungs.