Cough

A cough is a protective reflex that clears the throat and airways of irritants, mucus, or foreign material. Coughs can be acute (lasting less than three weeks), subacute (three to eight weeks), or chronic (longer than eight weeks). Symptoms vary from a dry, hacking cough to a productive cough with mucus or blood-streaked sputum.

• Common causes: Viral infections (cold, flu), bacterial infections (pneumonia, pertussis), allergies, asthma.
• Chronic causes: Chronic bronchitis, COPD, gastroesophageal reflux disease (GERD), postnasal drip, smoking.
• Serious causes: Lung cancer, tuberculosis, heart failure.
• Risk factors: Smoking, secondhand smoke, exposure to dust or pollutants, weakened immune system, chronic lung or heart conditions.

Seek medical evaluation if a cough lasts more than three weeks, produces blood, is associated with chest pain or shortness of breath, or is accompanied by high fever, night sweats, or weight loss. Infants, older adults, and people with chronic illnesses should be evaluated sooner if symptoms are severe