Colds are viral infections of the nose and throat. Colds can go on to involve the sinuses, ears, larynx (vocal cords), trachea and bronchi directly or through secondary effects.
The presence of the virus causes inflammation of membrane linings in the nose, so that there is swelling with obstruction (stuffiness) and increased mucous secretions.
Colds are the most common type of respiratory infection. They’re usually mild illnesses that naturally come to an end, only occasionally leading to further problems.
Reviewed by Cape Town-based general practitioner, Dr Dalia Hack. March 2019.