Jen Corace

Alarmist scenario: Lung cancer or emphysema.
More likely cause: A cold, acute bronchitis, postnasal drip from a cold or allergies, or acid reflux.
Reality check: “Symptoms of lung cancer do not come on suddenly,” says pulmonologist Norman H. Edelman, the chief medical officer for the American Lung Association. “Cigarette smoking causes 87 percent of lung cancers, so if you don’t smoke, your risk is low.” Smoking is also the leading cause of emphysema.
Rx: If your cough lasts more than four weeks, see a doctor. “If you cough mostly at night, avoid eating within three hours of bedtime, since gastric reflux can contribute to a cough,” says Edelman.