metallic
Meaning of metallic: A taste of coins or blood with nothing metal in the mouth, arising from the taste and smell pathways rather than the food.
Definition of metallic
Metallic describes something made of metal or resembling metal, and in clinical use it nearly always describes a taste. A metallic taste is a distortion of flavor in which food, drink or even plain water seems to taste of coins, tin or blood. The sensation is generated inside the taste and smell pathways, so it persists whatever is eaten and cannot be rinsed away.
What causes it?
| Cause | How it comes about |
|---|---|
| Chemotherapy, platinum drugs especially | Drug enters saliva and disturbs fast-renewing taste cells |
| Radiation to the head or neck | Taste buds and salivary glands lie inside the treated area |
| Certain medicines | Metronidazole and metformin are among those commonly reported |
| Zinc deficiency | Zinc is needed for taste cells to renew normally |
| Bleeding gums or dental work | Iron in blood, or different metals sitting in wet mouth tissue |
| Advanced kidney failure | Waste products accumulate and alter the saliva |
Why does it change flavor at all?
Taste cells are among the shortest-lived cells in the body, replaced over a week or two, so anything that slows cell renewal reaches them early. Saliva matters as much as the cells, because a substance has to dissolve before it can be tasted, and drugs and their breakdown products are carried into saliva from the blood. Smell then supplies most of what is experienced as flavor, traveling up the back of the throat while food is chewed. Damage anywhere along that chain arrives at awareness as a taste complaint, which is why the sensation is described as coming from the mouth even when the mouth is healthy. Loss of appetite and weight commonly follow, since familiar foods no longer taste as expected. Among people treated for cancer the change is one of the most frequently reported and least anticipated effects.
Where else is the word used?
Two other uses turn up in notes and are unrelated to taste. A metallic tinkling quality to bowel sounds is described when loops of intestine above a blockage are stretched and fluid drops through them under tension. A metallic click heard over the chest describes the sound of an artificial heart valve closing, audible at the bedside and sometimes to the person carrying it.
Also known as
Used in a sentence
The patient described a persistent metallic taste beginning in the days after the infusion.
Good to know
A metallic taste reflects a change inside the taste and smell pathways rather than anything in the food, and because smell supplies most of what is perceived as flavor, loss of smell is frequently reported as a taste problem.
Word origin
Where “metallic” comes from
From the Greek metallon, meaning a mine or a metal, through the Latin metallum.