Dysgeusia
What Is It?
Dysgeusia (pronounced "dis-GOOZ-ee-a") is any distortion in the perception of taste. It can include:
- A metallic taste
- A bad taste (cacogeusia)
- Complete loss of taste (ageusia)
- Things taste "wrong"
- Things taste stronger than they should (hypergeusia)
In some patients with dysgeusia, the sense of smell also can be altered. Nerve cells involved in the sense of smell are called olfactory cells. Gustatory and olfactory cells work together to produce the sense of taste. Our taste cells can only identify four sensations: sour, bitter, salty and sweet. The subtleties of flavor come from your sense of smell. To understand the connection between taste and smell, try taking a sip of coffee or eating an orange slice while you hold your nose. It will be difficult for you to taste the flavor of the food or drink.
Dysgeusia can be a symptom of some other problem or a side effect of another condition or medication. Dysgeusia is relatively common and can have numerous causes, many of which are temporary. For example, the common cold, flu, a nasal or sinus infection, strep throat or other short-lived conditions can affect the sense of taste. Other causes include:
- Smoking
- Gingivitis or periodontal (gum) disease
- Certain medications, including lithium, antibiotics, ACE inhibitors and many chemotherapy drugs
- Dry mouth (xerostomia), which also can be caused by many medications
- Vitamin or mineral deficiency
- Conditions that affect the face or throat, such as Sjögren's syndrome or Bell's palsy
- A brain tumor or trauma to the head
- Damage to the taste nerves
- Metabolic problems, such as diabetes, thyroid disease or liver problems
- Depression
- Laryngectomy (removal of the voice box)
- Dysgeusia may also be associated with burning mouth syndrome or glossitis, and other oral conditions.
The alterations in the sense of taste (and sometimes smell) are the only symptoms.
Diagnosis
Your doctor will take a medical history, perform a physical exam and ask you detailed questions about your dysgeusia — how long you've noticed it, what kind of taste changes you've noticed, and possible causes (such as smoking, cold or flu or other conditions).
Tests are available to evaluate your senses of taste and smell. Certain chemicals made to produce the four major tastes - sour, sweet, bitter, salty — can be applied to areas of your tongue. Or you may be asked to take a taste test, in which you sip certain test liquids and try to identify their tastes. Your doctor can use a "scratch and sniff" test to evaluate your sense of smell. The test consists of cards, each containing an odor that is released when scratched. You are asked to identify the odor on each card.
Prevention
Some causes of dysgeusia can be prevented, but most cannot. Quitting smoking will improve your senses of taste and smell. Practicing good oral hygiene, getting regular dental care, and having sinus problems treated also can help.
Treatment
Many times, dysgeusia is treated by treating the underlying cause. If the underlying cause is not treatable — for example, if you have irreversible nerve damage — your dysgeusia cannot be treatable either, although it may go away or be tolerated.
Credit: National Institute of Health.