What causes loss of appetite?

Short-term appetite loss often accompanies infections such as influenza, COVID-19, gastroenteritis, or hepatitis A. Nausea, vomiting, diarrhoea, abdominal pain, or fever can make food unappealing. Gastritis may cause upper-abdominal discomfort, nausea, or early fullness. Depression can reduce interest in food and may occur with low mood, poor sleep, or loss of pleasure.

Persistent appetite loss can also occur with medicine side effects, dental problems, swallowing difficulty, or conditions that alter body chemistry. High calcium in cancer may cause thirst, constipation, nausea, weakness, or confusion. These possibilities are not a diagnosis; the duration and accompanying symptoms matter.

Try small, frequent meals and choose foods with a smell, texture, and temperature you can tolerate. Sip fluids regularly, especially after vomiting or diarrhoea. Keep track of what you manage to eat, related symptoms, medicines, and any change in weight or energy. Do not stop prescribed treatment without advice. Arrange a review if appetite does not return, eating becomes difficult, or daily functioning is affected.

Seek urgent care for severe abdominal pain, repeated vomiting, blood in vomit or stool, yellow skin or eyes, confusion, fainting, or signs of serious dehydration such as very little urine. Prompt assessment is also sensible with persistent appetite loss, marked weakness, ongoing fever, or unplanned weight loss. A clinician can examine you and decide whether blood tests or other checks are appropriate.

Ask whether your symptoms suggest infection, digestive irritation, mood-related appetite change, or a medicine effect; how to maintain nutrition and fluids; which tests may help; and what change should bring you back sooner.