Ageusia means the loss of taste. Those who suffer from ageusia cannot taste foods. Their taste buds no longer can taste or tell the difference between sourness, bitterness, saltiness, sweetness or unami. Often times this is also a result of the loss of smell. This problem can be a result of damage to the nerves that support the tongue, zinc and vitamin B3 deficiency, side affects of medication, anxiety disorders, and excessive alcohol and tobacco use. There are several ways to fix this problem depending on the cause.