Table 1. The most commonly occurring causes of acquired olfactory dysfunction in otorhinolaryngology*.

Cause	Relative frequency
Sinunasal conditions (inflammations of the nose and nasal sinuses, non-inflammatory respiratory disorders)	67%
Viral infection of the upper respiratory tract	14%
Idiopathic	8%
Trauma	6%
Iatrogenic	3%

*Modified from (10)