Fatigue and no appetite: causes and next steps

COVID-19 may cause tiredness and reduced appetite during an acute illness. Anaemia can limit oxygen delivery and contribute to low energy, while chronic kidney disease can affect appetite and wellbeing. Coeliac disease may cause digestive symptoms and nutritional problems. Burnout and alcohol use disorder can alter sleep, mood, and eating. Chronic fatigue syndrome has a more persistent pattern and may include worsening after exertion. Dehydration can itself cause weakness, dizziness, thirst, and reduced intake.

Consider what changed first: an infection, workload, mood, medicine, diet, alcohol use, or fluid intake. Symptoms such as fever, pain, diarrhoea, breathlessness, bleeding, or urinary changes help guide assessment.

Sip fluids often and take small portions of foods you can tolerate. Choose nourishing options such as yoghurt, soup, eggs, beans, or a smoothie, and avoid skipping all intake because appetite is absent. Rest and keep activity gentle. Record symptoms and medicines, and arrange a review if eating and drinking remain difficult or energy does not return.

Seek urgent help for fainting, confusion, severe weakness, chest pain, serious breathing difficulty, repeated vomiting, or very little urine. Arrange medical advice for persistent fatigue, ongoing appetite loss, unexplained weight change, or symptoms that limit daily activities.

Could my symptoms relate to hydration, medicines, mood, anaemia, kidney function, or nutrition? What examination or tests are appropriate? How should I maintain fluids and food while waiting for improvement?