[Diagnosis of non intentional weight loss in adults]

Significant non intentional weight loss in adults is a problem encountered frequently in clinical practice that poses a diagnostic challenge for the clinician. Causes are quite diverse, as are the prognostic implications. Cancer, gastrointestinal disease, and psychiatric problems were the three most common diagnoses, but a significant proportion of patients had no clear cause of their weight loss. The prognosis of this subset is generally favourable. Ruling out malignancy is one of the prime tasks. The investigation is based on a rational stepwise approach with a detailed history, a meticulous physical examination and a simple, non-invasive screening battery of tests (laboratory tests and medical imaging). A completely normal laboratory screening argues against severe organic disease in general and malignancy in particular. Additional testing should be targeted towards areas of concern raised by the initial evaluation. If this baseline examination is normal and reassuring, a strategy of careful clinical follow-up is preferred to non-targeted additional more invasive or expensive investigations.