The majority of flavor perception is derived from odorants. Thus, many patients who present with a complaint of taste loss in actuality have smell loss and require olfactory testing.
Dysgeusias are typically characterized by qualities identifiable by the taste system and should be described as either salty, sweet, sour, bitter, savory, or possibly metallic. Any other descriptors, such as "foul" or "rancid," are more likely to be associated with the olfactory system and should be classified as parosmias.