Fatigue and loss of appetite: what to know

A short-lived infection can reduce appetite while your body uses energy for recovery. Gastroenteritis may add vomiting or diarrhoea, while influenza and COVID-19 can bring fever, aches, or respiratory symptoms. Gastritis or a peptic ulcer may cause upper-abdominal discomfort, nausea, or early fullness. Depression can change sleep, motivation, and eating patterns. Hepatitis A may cause marked tiredness with nausea, abdominal discomfort, dark urine, or yellowing of the eyes. Pancreatic cancer is an uncommon but important cause of ongoing appetite loss with fatigue, particularly when weight loss or persistent abdominal symptoms are present. These conditions present with appetite loss in different ways; the symptom alone does not identify the cause.

Sip fluids regularly and choose small, nourishing meals rather than waiting for a strong appetite. Soft foods, soups, yoghurt, eggs, or other familiar options may be easier to manage. Rest, but keep gentle movement if you can do so safely. Record when symptoms began, what you eat and drink, bowel changes, fever, pain, sleep, medicines, and any weight change. Arrange a primary-care appointment if eating remains difficult, fatigue interferes with daily tasks, or symptoms keep returning. A clinician may review your history, examine you, and decide whether tests are appropriate.

Seek urgent medical help for severe or worsening abdominal pain, repeated vomiting, fainting, confusion, trouble breathing, blood in vomit or stool, or signs of significant dehydration such as very little urine. Prompt assessment is also warranted for yellow skin or eyes, dark urine with pale stools, or inability to keep fluids down. Contact a clinician soon for unplanned weight loss, persistent fever, or fatigue that is steadily limiting normal activities.

Could my medicines, mood, digestion, or a recent infection explain these symptoms? What warning signs should I monitor? Would an examination or blood tests help clarify the cause? How can I maintain hydration and nutrition while my appetite is low?