<unk>  (also known as parageusia) refers to alteration in the sense of taste. This includes ageusia (lack of sense of taste) and hypogeusia (decrease in sense of taste).
Can be primary or secondary in nature.
Dysgeusia
Drugs, including chemotherapeutic agents
Dysphonia
Zinc deficiency
Ergotism
Oral infections
Priapism
Upper respiratory infections 