What causes unintentional weight loss?

Weight may fall when you eat less, absorb fewer nutrients, or use more energy than usual. Depression can reduce appetite and change eating patterns. An overactive thyroid can increase energy use and may occur with heat intolerance, tremor or a racing heartbeat. Type 1 or Type 2 Diabetes may cause thirst and frequent urination alongside weight change. Ongoing diarrhoea, abdominal pain or poor absorption can occur with Crohn's Disease or Ulcerative Colitis. Persistent fever, night sweats or cough need assessment for infections such as Tuberculosis or HIV Infection. Several causes can overlap, so the pattern and accompanying symptoms matter.

Arrange a medical appointment if weight is falling without a clear explanation, especially when appetite, bowel habits, thirst, mood or energy have changed. Keep a simple record of meals, weight trend, medicines, alcohol intake and other symptoms. Continue regular nourishing meals and fluids if you can, but do not rely on supplements to replace an assessment. A clinician may review your history, examine you and choose tests based on the pattern.

Seek urgent care for severe weakness, confusion, fainting, inability to keep fluids down, vomiting blood, black stools, or difficulty breathing. Prompt assessment is also appropriate for persistent fever, drenching night sweats, a new lump, severe abdominal pain or rapidly worsening weight loss.

Ask which causes fit your symptoms, whether any medicine could be affecting appetite or digestion, and which checks are appropriate. Bring your weight history and a list of medicines and supplements.