What are taste disorders?

Taste disorders are those that result in an increase, decrease, absence or change in our sense of taste. Taste and smell are two senses that can be almost impossible to separate, so often these are referred to as smell and taste disorders. Common taste disorders include:

• Hypogeusia (loss or reduction in taste sense)
• Dysgeusia (having an abnormal taste)

In general, taste disorders can be described as being either an increased or decreased sensitivity to sweetness, bitterness, saltiness and sourness. Sometimes, people can describe having a metallic taste in their mouth. 

How are taste disorders caused?

Common causes of taste disorders are:

• Smoking
• The common cold
• Sinus infection
• Poor oral hygiene
• Recreational drug use (e.g. cocaine)
• Certain medications 
• Neurological disorders

What neurological disorders affect taste?

Neurological conditions that affect taste include:

• Head trauma
• Facial and trigeminal nerve impairment
• Neurogenerative disorders.

Specific neurodegenerative disorders that affect taste include:

• Frontal temporal dementia
• Parkinson's disease
• Alzheimer's
• Lewy Body Disease.

What other conditions could having a taste disorder indicate?

Taste disorders could be a symptom of various other medical conditions:

Hay fever

A metallic taste may be experienced because of inflamed nasal passages and problems with smell.

Vitamin B-12 deficiency

If the deficiency is severe, it may begin affective the nerves which may result in a metallic taste. 

Pregnancy

People in the first trimester of pregnancy commonly experience a metallic taste in the mouth.

Kidney failure

Waste materials can build up in the blood and this can cause a person to have a metallic taste. 

Cancer treatment

People that undergo chemotherapy, radiation therapy or both for cancer treatment have changes in taste. This is a temporary change and normal taste should return. 

How are taste disorders treated?

A metallic taste that result from taste disorders are treated depending on the underlying causes. For example:

• Treatments like allergy medication and avoiding allergy triggers are useful if you experience metallic taste with hay fever.
• If a patient has sinus, upper respiratory, and ear infections, decongestants and saline rinse can help. 
• Individualised treatment plans are put into place for neurological disorders.
• Taste disorders caused vitamin B-12 deficiency can be addressed via vitamin B-12 supplements or food that is high in this nutrient.
• If you experience taste issues because of kidney disease, things like dietary changes, blood pressure control and medications can help. 

Home remedies are also recommended for taste disorders caused by cancer treatment, side effects from medicines and pregnancy.