The Science Behind Lingering Coughs After a Cold.
Coughs can linger after a cold due to lingering inflammation caused by viral and bacterial infections that irritate the mucous membranes in the airway and nose, producing mucus. Airway inflammation may take a few weeks to subside, and this time could be extended if someone has had previous lung infections or is a smoker. Home remedies such as nasal saline, nasal steroids, and throat lozenges can help relieve symptoms. Coughing serves an immune function, but people should see a doctor if a cough lasts more than three to four weeks and is accompanied by other symptoms.