Why Your Favourite Foods Taste Strange When You Are Sick

Taste and Smell Work as a Team

Your tongue detects five basic tastes: sweet, salty, sour, bitter and umami. But the rich identity of most foods comes largely from aroma compounds reaching the smell receptors in your nose. (ncbi.nlm.nih.gov)

When you chew food, volatile molecules travel from the back of your mouth towards the nasal cavity. This pathway, known as retronasal olfaction, is crucial to flavour perception.

That is why holding your nose while eating can make food seem remarkably bland. You can still detect sweetness or saltiness, but much of the food's character disappears.

A Blocked Nose Can Change Everything

During a cold, the nasal passages can become swollen and congested. This makes it harder for aroma molecules to reach the olfactory receptors.

The result can feel like a sudden loss of taste, even though the primary problem is actually reduced smell. Research has shown that people with respiratory infections commonly report disturbances in smell and taste, particularly when nasal symptoms are present. (pubmed.ncbi.nlm.nih.gov)

This explains why a meal may start tasting normal again as your blocked nose clears.

Illness Can Affect Taste Directly Too

Smell is not the only factor. Taste disturbances can occur during infections and may involve changes in taste receptor function, inflammation or the local environment inside the mouth.

Saliva also plays an important role because taste molecules need to dissolve before they can interact effectively with taste receptors. Fever, dehydration and some medicines can alter saliva production and contribute to an unusual mouth sensation.

Certain medications are also known to cause taste disturbances as a side effect. Some can leave a bitter, metallic or otherwise altered taste.

Why Everything Can Taste "Wrong"

Being ill can also change your perception of foods you normally enjoy. If aroma information is reduced, the balance between sweet, salty, sour, bitter and umami becomes more prominent.

Imagine eating a curry while your sense of smell is severely reduced. You may still recognise chilli heat or saltiness, but the complex aromas of cumin, coriander, garlic and other spices become much harder to detect.

This is why people often describe sick-day food as tasting flat rather than simply tasteless.

COVID-19 Made This Effect Especially Noticeable

The COVID-19 pandemic brought widespread attention to smell and taste disturbances because these symptoms became strongly associated with the infection. Studies have documented both reduced smell and altered taste following SARS-CoV-2 infection, although the severity and duration vary considerably between people. (pubmed.ncbi.nlm.nih.gov)

For most ordinary colds, flavour gradually returns as congestion and inflammation settle.

When a Changed Taste Needs Attention

Temporary changes during illness are common, but a persistent or unexplained loss or distortion of taste or smell deserves medical attention, particularly if it continues after other symptoms have disappeared.

For everyday sickness, however, the experience is a useful reminder of just how sophisticated flavour really is. Your tongue is only one part of the system.

When you are ill, food has not necessarily lost its flavour. Your brain may simply be receiving fewer of the signals that normally tell it what that flavour is.