Glossitis of the tongue in iron deficiency anemia has been described as diffuse or patchy atrophy with tenderness or burning. One cause of iron deficiency anemia is sideropenic dysphagia (Plummer–Vinson or Paterson–Brown–Kelly syndrome) which is also characterized by esophageal webbing and dysphagia. Pernicious anemia is usually caused by autoimmune destruction of gastric parietal cells. Parietal cells secrete intrinsic factor which is required for the absorption of vitamin B12. Vitamin B12 deficiency results in megaloblastic anemia and may present as glossitis. The appearance of the tongue in vitamin B12 deficiency is described as "beefy" or "fiery red and sore". There may be
Philosophy of medicine populations in order to study their causes as well as how to manage, control, ameliorate the problems identified under study. Clinical medicine, as presented above, is part of a reductionist approach to disease, based ultimately on Cartesian dualism which says that the proper study of medicine is an investigation of the body when the latter is viewed as machine. A machine can exhaustively be broken down into its component parts and their respective functions; in the same way, the dominant approach to clinical research and treatment assumes the human body can be broken down/analysed in terms of its component parts