Ageusia is the loss of which sense?

Ageusia is the complete loss of the sense of taste. The word comes from the Greek roots a- meaning “without” and geusis meaning “taste.” A person suffering from ageusia is unable to detect any of the five main tastes — sweet, sour, salty, bitter, and umami. It is a rare condition because most people who experience changes in taste usually have hypogeusia (reduced sense of taste) or dysgeusia (distorted sense of taste) rather than total loss.

The sense of taste is controlled by taste buds, which are located mainly on the tongue and connected to the gustatory nerves. These nerves send signals to the brain, allowing humans to identify different flavors. When these nerves are damaged or when the pathways to the brain are affected, ageusia can occur.

Common causes of ageusia include:

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  Infections such as colds, sinusitis, or COVID-19

  
  


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  Nerve damage due to head injury or neurological disorders

  
  


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  Vitamin deficiencies, especially zinc

  
  


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  Exposure to certain medications or chemicals

  
  


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  Smoking or poor oral hygiene

  
  

Sometimes, ageusia can also appear after respiratory illnesses or dental problems. Since the sense of taste is closely related to the sense of smell, loss of smell (anosmia) may also cause partial loss of taste perception, but true ageusia means taste is completely gone even when smell remains normal.

Taste plays an important biological role by helping humans detect spoiled food and enjoy eating. Understanding ageusia helps in studying how the nervous system, taste receptors, and brain work together.

Therefore, the correct answer is Taste, as ageusia refers to the complete loss of this particular sense in humans.