In COPD, there is an increase in airway resistance , shown by a decrease in the forced expiratory volume in 1 second (FEV1) measured by spirometry . COPD is defined as a forced expiratory volume in 1 second to forced vital capacity ratio (FEV1/FVC) that is less than .  The residual volume, the volume of air left in the lungs following full expiration, is often increased in COPD, as is the total lung capacity, while the vital capacity remains relatively normal. The increased total lung capacity (hyperinflation) can result in the clinical feature of a "barrel chest" - a chest with a large front-to-back diameter that occurs in some individuals with COPD. Hyperinflation can also be seen on a chest x-ray as a flattening of the diaphragm .
In stage IIIB, chemoradiation therapy is considered first line. Radiation therapy alone may be used if patients are concerned with the toxic effects of chemotherapy; however outcomes are better if both treatment modalities are used. In this stage of NSCLC, surgery is not considered a curative intervention or effective treatment and is rarely performed. Radiation therapy may be used for palliation of symptoms when tumor invades certain tissues and causes troublesome symptoms.
Avoid things that make your asthma worse. Common asthma triggers are tobacco smoke, animal dander, dust mites, air pollution, mold, and pollens. You can try "fragrance-free" products if your asthma is triggered by fragrances. Talk to your doctor about allergy shots if your asthma symptoms are linked to allergens that you cannot avoid. The shots may lessen or prevent the symptoms but will not cure the asthma. You can reduce your exposure to air pollution by limiting your outdoor activities on days when the air quality in your neighborhood is poor.