Dysgeusia is a condition where a person’s perception of taste is altered; everything seems sweet, sour, bitter, or metallic.
Taste disorders are common in adults. A study performed on adults in the United States indicated that up to 17 percent of those tested had some impairment in taste. Impaired taste can take many forms, including:
- Hypogeusia, which is a reduced or diminished sense of taste
- Ageusia, which is a complete loss of taste
- Aliageusia, when a typically pleasant-tasting food or drink begins to taste unpleasant
- Phantogeusia, which refers to tasting something that is not actually there, or hallucinating a particular taste
The tongue and throat have many taste receptors. Three different nerves contribute to the sensation of taste depending on where in the mouth the taste receptors are located. The front of the tongue is innervated, or supplied, by cranial nerve VII, called the facial nerve, through the chorda tympani; the back part of the tongue is innervated by cranial nerve IX, called the glossopharyngeal nerve; and the palate and throat are innervated by cranial nerve X, called the vagus nerve.
Completely losing taste due to injury of a nerve is rare since several nerves are involved. What some people consider a “taste,” such as “hot and spicy” or “chemical,” may be detected through pain and other receptors working through a completely different nerve, cranial nerve V, called the trigeminal nerve. There are even some taste receptors in the nose, but doctors are still figuring out exactly what role they play.
Humans can detect five different tastes: sweet, salty, bitter, sour, and savory, or umami. It is important to recognize the difference between taste and flavor. Flavor is a multisensory experience that combines both the smell and taste of foods and drinks. While eating, the smell of food is detected through both the front of the nose and the back of the throat. Depending on the path the smell takes, it can have a different effect. When people lose their sense of smell, they often complain of a loss of taste but what they really mean is that they have lost that combination of smell and taste, or flavor.
What are the Symptoms of Dysgeusia?
The symptoms of dysgeusia can include:
- Food has lost its characteristic sweetness or saltiness
- Foods that used to taste good now taste bad (sour or rotten)
- Foods taste metallic
- A taste is present despite not eating anything
What Causes Dysgeusia?
What Are the Treatment Options?
The treatment options for an impaired sense of taste depend on the exact cause for the dysgeusia or hypogeusia. With mineral or vitamin deficiencies, simply supplementing with a multi- or specific vitamin (B12, B-complex, and zinc) may be helpful. If due to medications, switching to a different medication may help restore a normal sense of taste. Managing other disorders that can trigger loss of taste, such as diabetes, thyroid disorders, or kidney problems, may also lead to improvement.
Reducing or stopping smoking or other forms of tobacco use as well as managing acid reflux either with medications or dietary modifications cannot be overemphasized. Drinking plenty of water can also help with dry mouth due to Sjogren’s, radiation treatment, or age-related loss of taste.