Causes of loss of appetite and weight loss

Short-term infections such as influenza, COVID-19, gastroenteritis, or hepatitis A may reduce appetite through fever, nausea, altered taste, or tiredness. Gastritis and peptic ulcer can make eating uncomfortable, while ongoing indigestion or abdominal pain may lead someone to avoid food. Depression can affect appetite, energy, sleep, and interest in daily activities. Less commonly, persistent appetite loss and weight loss can occur with a serious illness such as pancreatic cancer. The meaning depends on how quickly weight changed, whether it was intended, and symptoms such as vomiting, diarrhoea, pain, jaundice, fever, thirst, or low mood.

Keep a simple record of meals, symptoms, weight trend, bowel changes, and medicines. Choose small, frequent meals and fluids if large portions feel difficult, unless a clinician has given different dietary advice. Treating nausea, pain, mouth problems, or low mood may help intake, but the cause should still be assessed when weight loss is unplanned. Book an appointment if appetite remains low, eating is painful, or your clothes are becoming looser without intending to lose weight.

Seek urgent help for severe abdominal pain, vomiting blood, black stools, confusion, fainting, inability to keep fluids down, or signs of serious dehydration. Prompt medical review is needed for yellow skin or eyes, persistent fever, progressive weakness, or weight loss that continues without explanation. If low appetite comes with hopelessness or thoughts of self-harm, seek immediate mental-health support or emergency care. These symptoms do not identify one diagnosis, but they should not be ignored.

Ask what might explain the appetite change and whether your medicines, digestion, mood, or recent infection could contribute. Share the timing of weight loss and any pain, bowel symptoms, fever, or changes in taste. Ask which tests or nutritional support may be useful and what warning signs should prompt urgent care.