A cough is a common, irritating symptom that can be either short-term or chronic. Short-term causes of cough may include viruses (including the flu, the common cold, croup, and RSV), bacterial infections such as pneumonia, bronchitis, or sinusitis, and allergic rhinitis. Chronic coughs lasting longer than 8 weeks could include asthma, allergies, chronic sinus infections, GERD, congestive heart failure, emphysema, lung cancer, or tuberculosis.