Anorexia is an abnormal loss of the appetite for food. Anorexia can be caused by cancer, AIDS, a mental disorder (i.e., anorexia nervosa), or other diseases.
Cancer and cancer treatments may affect taste, smell, appetite, and even the ability particularly in oral cancers, to eat enough food or absorb the nutrients from food. This can cause malnutrition, a condition caused by a lack of consuming by mouth or through supplemental feeding systems like PEG tubes, key nutrients. Malnutrition can cause the patient to be weak, tired, and unable to fight infections or even get through cancer treatment. Malnutrition may be made worse if the cancer grows or spreads. Eating too little protein and calories is a very common problem for cancer patients, particularly oral cancer patients as they develop painful mucositis sores in their mouths during treatments that can persist for some period during and after the completion of treatment. The sores make it very painful to take nutrition by mouth. Having enough protein and calories is important for healing, fighting infection, maintaining lean body mass, and having enough ene