[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [General pathology](https://durgical.com/en/general-pathology/) › [Nutritional pathology](https://durgical.com/en/general-pathology/#a-nutrition) › Cachexia, anorexia nervosa and bulimia [General pathology](https://durgical.com/en/general-pathology/) · [Nutritional pathology](https://durgical.com/en/general-pathology/#a-nutrition) # Cachexia, anorexia nervosa and bulimia - Topic Cachexia is inflammatory wasting that eating alone does not reverse; anorexia and bulimia are eating disorders with serious body effects. Updated 2026-11-01 ## Key points - Cachexia ≠ starvation: cytokine-driven, it does not reverse with extra food alone. - Anorexia nervosa: amenorrhoea from low GnRH, osteoporosis, bradycardia, lanugo, refeeding risk. - Bulimia: hypokalaemic hypochloraemic metabolic alkalosis, parotid enlargement, enamel erosion, Russell sign. - Sudden death in eating disorders is often arrhythmic (hypokalaemia, prolonged QT). ## What it is Cachexia accompanies cancer, heart failure, COPD, chronic kidney disease and HIV: cytokines break down muscle and fat even when the patient eats. Anorexia nervosa is self-imposed starvation with endocrine, bone and heart consequences; bulimia nervosa combines binge eating with purging, whose main dangers are electrolyte disturbances and injury to the upper digestive tract. ## Step by step - Tumour or chronic disease activates macrophages and lymphocytes. - TNF, IL-6 and IL-1 act on the hypothalamus (less appetite) and on muscle and fat. - The ubiquitin–proteasome system breaks down muscle proteins; lipolysis empties fat cells. - The liver switches to acute phase proteins; albumin falls. - Weakness, fatigue and poor treatment tolerance follow, and survival falls. ## Three forms of weight-related disease | Condition | Core mechanism | Typical findings | | --- | --- | --- | | Cachexia | Cytokines (TNF, IL-6, IL-1) and tumour factors increase muscle breakdown | Muscle and fat loss not reversed by feeding, weakness, anaemia | | [Anorexia nervosa](https://durgical.com/en/conditions/anorexia-nervosa/) | Restriction leads to a starvation state and low GnRH | Amenorrhoea, osteoporosis, bradycardia, hypotension, lanugo, low T3 | | [Bulimia nervosa](https://durgical.com/en/conditions/bulimia-nervosa/) | Binge eating with vomiting, laxatives or diuretics | Often normal weight, hypokalaemic metabolic alkalosis, parotid swelling, enamel erosion, knuckle calluses | ## Clinical notes - In anorexia nervosa, low oestrogen and high cortisol cause bone loss that may not fully recover. - Repeated vomiting can tear the oesophageal mucosa (Mallory-Weiss) or rupture the oesophagus. - Refeeding a severely underweight patient carries the risk of low phosphate, potassium and magnesium. ## Memory aid In cachexia the body consumes itself despite the food; in anorexia it is denied the food; in bulimia it throws the food away. ## Test yourself Think of the answer, then tap the question to see it. ## Why does extra feeding not reverse cancer cachexia? The wasting is driven by cytokines and tumour factors that keep muscle breakdown and lipolysis active, not only by low intake. ## Which acid–base disorder is typical of repeated self-induced vomiting? Hypokalaemic, hypochloraemic metabolic alkalosis from loss of gastric acid and volume. ## Why do women with anorexia nervosa stop menstruating? Starvation suppresses hypothalamic GnRH, so LH, FSH and oestrogen fall. ## What is Russell sign? Calluses or scars on the knuckles from repeatedly using the hand to induce vomiting. [Add to my cards (4)](https://durgical.app/estudiar/?add=/en/general-pathology/cachexia-anorexia-nervosa-and-bulimia/) ## Related - [Local effects of tumours and cancer cachexia](https://durgical.com/en/general-pathology/local-effects-of-tumours-and-cancer-cachexia/) - [Atrophy](https://durgical.com/en/general-pathology/atrophy/) - [Severe acute malnutrition: marasmus and kwashiorkor](https://durgical.com/en/general-pathology/severe-acute-malnutrition-marasmus-and-kwashiorkor/) - [Systemic effects of inflammation: fever, acute-phase proteins, leukocytosis, sepsis](https://durgical.com/en/general-pathology/systemic-effects-of-inflammation-fever-acute-phase-proteins-leukocytosis-sepsis/) ## Related conditions - [Anorexia nervosa](https://durgical.com/en/conditions/anorexia-nervosa/) - [Bulimia nervosa](https://durgical.com/en/conditions/bulimia-nervosa/) - [Binge-eating disorder](https://durgical.com/en/conditions/binge-eating-disorder/) - [Refeeding syndrome](https://durgical.com/en/conditions/refeeding-syndrome/) - [Hypokalaemia](https://durgical.com/en/conditions/hypokalaemia/) - [Metabolic alkalosis](https://durgical.com/en/conditions/metabolic-alkalosis/) - [Osteoporosis](https://durgical.com/en/conditions/osteoporosis/) - [Functional hypothalamic amenorrhoea](https://durgical.com/en/conditions/functional-hypothalamic-amenorrhoea/) - [Mallory-Weiss syndrome](https://durgical.com/en/conditions/mallory-weiss-syndrome/) - [Oesophageal perforation (Boerhaave syndrome)](https://durgical.com/en/conditions/oesophageal-perforation/) - [Sarcopenia](https://durgical.com/en/conditions/sarcopenia/) - [Heart failure](https://durgical.com/en/conditions/heart-failure/) ## Elsewhere in DurgiPedia - [Ubiquitin–proteasome system](https://durgical.com/en/biochemistry/topics/ubiquitin-proteasome-system/) - [TNF-α](https://durgical.com/en/immunology/tnf/) - [Interleukin-6](https://durgical.com/en/immunology/interleukin-6/) - [Prolonged fasting and starvation](https://durgical.com/en/physiology/prolonged-fasting-and-starvation/) - [Appetite hormones: leptin, ghrelin and incretins](https://durgical.com/en/physiology/appetite-hormones-leptin-ghrelin-and-incretins/) [← All of general pathology](https://durgical.com/en/general-pathology/) Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given. Sources: [Nutrition in Cancer Care (PDQ®)–Health Professional Version](https://www.cancer.gov/about-cancer/treatment/side-effects/appetite-loss/nutrition-hp-pdq) (National Cancer Institute, 2026); [Anorexia: MedlinePlus Medical Encyclopedia](https://medlineplus.gov/ency/article/000362.htm) (MedlinePlus, US National Library of Medicine, 2026); [Bulimia: MedlinePlus Medical Encyclopedia](https://medlineplus.gov/ency/article/000341.htm) (MedlinePlus, US National Library of Medicine, 2026). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/general-pathology/cachexia-anorexia-nervosa-and-bulimia/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/general-pathology/cachexia-anorexia-nervosa-and-bulimia/