Bronchitis affects the bronchial tubes, while pneumonia affects the lung air sacs. Without treatment, bronchitis can become pneumonia. You’re coughing, you’ve got a fever, and your chest feels ...

A narrowing of the smallest airways in the lung (bronchioles) causes wheezing. This narrowing results from swelling caused by a virus. The respiratory syncytial virus (RSV) causes most bronchiolitis.

Figure 1. These emeralds from Musakashi, Zambia, range from 0.57 to 4.85 ct. The rough samples were polished with one window on each. The faceted sample measures 6.29 × 5.35 × 3.53 mm and weighs 0.97 ...