Poor appetite or not eating
This page is reference information compiled from the cited sources. It is not medical advice. For any decision about health, diagnosis or care, consult a qualified professional.
What it is
Anorexia is a medical term for loss of appetite. In this usage, anorexia is a symptom, not a diagnosis. Anorexia simply manifests as a decreased or loss of appetite. This can present as not feeling hungry or lacking the desire to eat. Sometimes people do not notice they lack an appetite until they begin to lose weight from eating less. In other cases, it can be more noticeable, such as when a person becomes nauseated from just the thought of eating. The symptom also occurs in non-human animals, such as cats, dogs, cattle, goats, and sheep. In these species, anorexia may be referred to as inappetence. As in humans, loss of appetite can be due to a range of diseases and conditions, as well as environmental and psychological factors.
Key facts
Many possible causes exist for a loss of appetite, some of which may be harmless, while others indicate a serious clinical condition or pose a significant risk. Appetite stimulation and suppression is a complex process involving many different parts of the brain and body by the use of various hormones and signals. Appetite is thought to be stimulated by interplay between peripheral signals to the brain, such as taste, smell, sight, and gut hormones, as well as the balance of neurotransmitters and neuropeptides in the hypothalamus. Examples of these signals or hormones include neuropeptide Y, leptin, ghrelin, insulin, serotonin, and orexins, also called hypocretins. Anything that causes an imbalance of these signals or hormones can lead to the symptom of anorexia. Common causes include abdominal pain, acute radiation syndrome, ADHD, Addison's disease, alcoholism, alcohol withdrawal, anemia, anorexia nervosa, anxiety, appendicitis, cancer, infection, influenza, depression, nausea, old age, stress, and side effect of drugs. Drugs associated with anorexia include stimulants, narcotics, antidepressants primarily selective serotonin reuptake inhibitors such as fluoxetine, Byetta, topiramate, and abrupt stopping of appetite-increasing drugs such as cannabis and corticosteroids. Other causes include allergy, altitude sickness, airsickness, toothache, psychological stress, and being in the presence of unappealing things such as waste matter, dead organisms, or bad smells. Complications of anorexia may result due to poor food intake. Poor food intake can lead to dehydration, electrolyte imbalances, anemia, and nutritional deficiencies. These imbalances will worsen the longer that food is avoided. Any form of decreased appetite that leads to changes in the body, such as weight loss or muscle loss, and is not done intentionally as part of dieting is clinically significant.
When to seek professional help
The source describes professional care when a patient begins to eat after prolonged starvation to avoid the potentially fatal complications of refeeding syndrome. The initial signs of refeeding syndrome are minimal, but can rapidly progress to death. Reinitiation of food or oral intake is usually started slowly and requires close observation under supervision by trained healthcare professionals. This is usually done in a hospital or nutritional rehabilitation center. The source notes that loss of appetite may indicate a serious clinical condition or pose a significant risk. Decreased appetite that leads to changes in the body, such as weight loss or muscle loss, and is not done intentionally as part of dieting is clinically significant. Poor food intake can lead to dehydration, electrolyte imbalances, anemia, and nutritional deficiencies, and these imbalances worsen the longer food is avoided. Anorexia can lead to dangerous electrolyte imbalances, acquired long QT syndrome, and sudden cardiac death, and the risk is further heightened when feeding resumes after a period of abstaining from consumption.
Source: Anorexia (symptom) (CC BY-SA 4.0 (Wikipedia)), retrieved 2026-11-05.
