Upper respiratory tract infection

An upper respiratory tract infection (URTI) is an illness caused by an acute infection, which involves the upper respiratory tract, including the nose, sinuses, pharynx, larynx or trachea. This commonly includes nasal obstruction, sore throat, tonsillitis, pharyngitis, laryngitis, sinusitis, otitis media, and the common cold.^: 28 Most infections are viral in nature, and in other instances, the cause is bacterial. URTIs can also be fungal or helminthic in origin, but these are less common.^{: 443–445}

In 2015, 17.2 billion cases of URTIs are estimated to have occurred. As of 2016, they caused about 3,000 deaths, down from 4,000 in 1990.