A condition in which the intestines fail to absorb nutrients, fluids, or both from food properly. Causes include pancreatic insufficiency, coeliac disease, Crohn’s disease, intestinal surgery, chronic infections, and certain medications. Symptoms range from diarrhoea, bloating, and fatty stools to weight loss and deficiencies of iron, calcium, vitamins A, D, E, K, and B12. Diagnosis involves blood tests, stool analysis, and sometimes endoscopy with biopsy. Treatment targets the underlying cause, supported by dietary modification such as low-fat or gluten-free diets, enzyme replacement, and supplementation of deficient nutrients. Early recognition prevents the long-term consequences of chronic undernutrition.