Extreme weight loss without trying: what to know

Weight can fall when appetite is reduced, swallowing is difficult, food is not absorbed well, or the body is using more energy during illness. Dental problems, stress, depression, thyroid disease, diabetes, infection, medicines, and digestive disorders are possible explanations. Cancer can also present with unexplained weight loss, including bowel, lung, oesophageal, pancreatic, and blood cancers, but weight loss alone does not establish a cancer diagnosis.

The clinician will usually consider the speed and pattern of change, appetite, thirst, bowel habits, swallowing, pain, cough, fever, night sweats, medicines, and mental wellbeing. An examination and targeted tests may be recommended rather than assuming one cause.

Book a medical appointment soon and take a record of weight readings, appetite, meals, symptoms, medicines, and recent stress or illness. Mention dental or swallowing difficulty and any change in bowel or urinary habits. Continue nourishing foods and fluids that you can manage; a dietitian can help if eating is difficult. Do not use supplements to mask ongoing weight loss without advice.

Seek urgent help for vomiting that prevents fluids, severe abdominal or chest pain, black or bloody stools, severe weakness, fainting, confusion, or difficulty breathing. Arrange prompt assessment for weight loss with persistent fever, drenching night sweats, a new lump, coughing blood, progressive swallowing trouble, or yellowing of the skin or eyes.

What causes fit my pattern of weight loss? Which checks or tests are appropriate? Could a medicine, swallowing problem, or digestive issue be involved? How can I maintain nutrition while we investigate? When should I return if the change continues?