What does this mean?
The tongue only picks out a few basic qualities such as sweet, salty, sour, bitter and umami. Most of what we call the taste of food is in fact smell, which travels up from the back of the throat to reach the area where smell is picked up. That is why what lies behind losing your sense of taste is most often not the taste buds but the pathway for smell.
A simple distinction helps: if you can still tell salt and sugar apart but cannot get the character of the food, the problem is most likely on the smell side, and a blocked nose, sinusitis or catarrh running down the back of the throat is considered. If you cannot tell salty from sweet either, the taste pathway itself may be affected.
For taste molecules to reach the buds they have to dissolve in saliva; when the mouth dries out, taste dulls too. A white coating on the tongue that can be scraped off, medicines newly started, inflammation under a denture and smoking all produce the same result. If the loss affects one side only, or begins immediately after a dental procedure, that brings the nerve pathway to mind and calls for a separate assessment.
The cause of lost taste can lie inside the mouth or outside it; whether it began suddenly or slowly, whether it affects one side or all of it, and any dryness, catarrh or recent procedure that goes with it make most of the distinction.
Likely causes
What helps at home?
- Clean your tongue gently once a day with a soft brush or a tongue cleaner, working from the back towards the front; if there is a patch that will not scrape off, do not force it.
- Drink water through the day and stimulate saliva with sugar-free gum; a dry mouth directly reduces how much taste you pick up.
- Make a list of the medicines you have recently started and compare it with the date your taste changed; do not stop a medicine on your own judgement.
- Stop or cut down on smoking and on mouthwash containing alcohol; both dry the lining and upset what you can taste.
- If numbness or weakness in your face comes with the loss of taste
- If the loss started immediately after a dental procedure and affects one side of your tongue
- If you have a sore in your mouth that will not heal, a patch that will not wipe off, or a hardened swelling
- If a one-sided, foul-smelling discharge from the nose and a feeling of pressure in the face come with it
- If you are losing weight because you cannot eat
Frequently asked questions
- Will my sense of taste come back?
- It depends on the cause. When reversible causes such as a dry mouth, a coating on the tongue or a fungal infection are dealt with, what you can taste most often improves. Where the smell pathway is involved, recovery can take weeks. With losses due to nerve injury the outcome varies and early assessment is advised; it would not be right to give a definite length of time in advance.
- I have a constant metallic taste in my mouth, is that loss of taste too?
- No, it is a different problem. In loss of taste what you perceive is reduced; a metallic or bitter taste that is there all the time is perception being distorted. This picture is seen more often alongside medicines, reflux, a dry mouth and certain conditions inside the mouth. Because telling the two apart changes the direction of the search, it matters that you describe to your dentist which one you are having.
- Should I take a zinc supplement?
- The decision about a supplement is made on blood results and on an assessment; a supplement taken where there is no deficiency is not expected to help. It is true that iron, B12 or zinc deficiency can lie behind loss of taste, but the way to that is through tests. Starting a supplement on your own judgement can delay finding the real cause.
This content is for general information and does not replace an in-person examination. Symptoms overlap between conditions, and a diagnosis can only be made clinically.