What should you know about virus loss of appetite?

During an infection, fever, nausea, a blocked nose, altered taste or smell, tiredness and stomach upset can make food less appealing. Loss of appetite can accompany influenza, COVID-19 or gastroenteritis, but it can also have non-infectious causes such as gastritis, an ulcer, depression or medication effects. The symptom alone cannot identify its cause.

The practical concern is reduced fluid and energy intake. Dry mouth, dark urine, dizziness, unusual sleepiness or passing urine less often can suggest dehydration and should not be ignored.

Take frequent sips of water or an oral rehydration drink if appropriate. Try small portions of bland or familiar foods, and include nourishing options when tolerated. Do not force a large meal. Rest, monitor vomiting or diarrhoea, and record what you can drink and keep down. People with diabetes, frailty, pregnancy or a long-term illness may need individual advice sooner.

A clinician can assess ongoing appetite loss and consider causes such as hepatitis A or another digestive condition.

Seek urgent help for confusion, fainting, severe weakness, breathing difficulty, blood in vomit or stool, severe abdominal pain, yellowing of the skin or eyes, or inability to keep fluids down. Arrange medical review when appetite remains poor, weight is falling without intention, swallowing is difficult, or symptoms keep returning.

Ask which cause best fits your other symptoms, how to protect hydration, whether medicines could be affecting appetite, and when you should be reviewed if eating does not return.