Polyphagia or hyperphagia is an abnormally strong, incessant sensation of

hunger In politics, humanitarian aid, and the social sciences, hunger is defined as a condition in which a person does not have the physical or financial capability to eat sufficient food to meet basic nutritional needs for a sustained period. In the ...

or desire to eat often leading to

overeating Overeating occurs when an individual consumes more calories in relation to the energy that is expended via physical activity or expelled via excretion, leading to weight gain and often obesity. Overeating is the defining characteristic of binge e ...

. In contrast to an increase in appetite following exercise, polyphagia does not subside after eating and often leads to rapid intake of excessive quantities of food. Polyphagia is not a disorder by itself; rather, it is a symptom indicating an underlying medical condition. It is frequently a result of abnormal blood glucose levels (both

hyperglycemia Hyperglycemia is a condition in which an excessive amount of glucose circulates in the blood plasma. This is generally a blood sugar level higher than 11.1 mmol/L (200 mg/dL), but symptoms may not start to become noticeable until even ...

and

hypoglycemia Hypoglycemia, also called low blood sugar, is a fall in blood sugar to levels below normal, typically below 70 mg/dL (3.9 mmol/L). Whipple's triad is used to properly identify hypoglycemic episodes. It is defined as blood glucose belo ...

), and, along with

polydipsia Polydipsia is excessive thirst or excess drinking.Porth, C. M. (1990). ''Pathophysiology: Concepts of altered health states''. Philadelphia: J.B. Lippincott Company. The word derives from the Greek () "very thirsty", which is derived from (, "mu ...

and

polyuria Polyuria () is excessive or an abnormally large production or passage of urine (greater than 2.5 L or 3 L over 24 hours in adults). Increased production and passage of urine may also be termed diuresis. Polyuria often appears in conjunction wit ...

, it is one of the "3 Ps" commonly associated with uncontrolled

diabetes mellitus Diabetes, also known as diabetes mellitus, is a group of metabolic disorders characterized by a high blood sugar level ( hyperglycemia) over a prolonged period of time. Symptoms often include frequent urination, increased thirst and increased ap ...

Etymology and pronunciation

The word ''polyphagia'' () uses combining forms of '' poly-'' + '' -phagia'', from the Greek words πολύς (polys), "very much" or "many", and φαγῶ (phago), "eating" or "devouring".

Underlying conditions and possible causes

Polyphagia is one of the most common symptoms of diabetes mellitus. It is associated with hyperthyroidism and endocrine diseases, e.g.,

Graves' disease Graves' disease (german: Morbus Basedow), also known as toxic diffuse goiter, is an autoimmune disease that affects the thyroid. It frequently results in and is the most common cause of hyperthyroidism. It also often results in an enlarged thyr ...

, and it has also been noted in Prader-Willi syndrome and other genetic conditions caused by chromosomal anomalies. It is only one of several diagnostic criteria for bulimia and is not by itself classified as an eating disorder. As a symptom of

Kleine–Levin syndrome Kleine–Levin syndrome (KLS) is a rare disorder characterized by persistent episodic hypersomnia and cognitive or mood changes. Many patients also experience hyperphagia, hypersexuality and other symptoms. Patients generally experience recurrent e ...

, it is sometimes termed megaphagia. Knocking out vagal nerve receptors has been shown to cause hyperphagia. Changes in

hormones A hormone (from the Ancient Greek, Greek participle , "setting in motion") is a class of cell signaling, signaling molecules in multicellular organisms that are sent to distant organs by complex biological processes to regulate physiology and beh ...

associated with the female

menstrual cycle The menstrual cycle is a series of natural changes in hormone production and the structures of the uterus and ovaries of the female reproductive system that make pregnancy possible. The ovarian cycle controls the production and release of eggs a ...

can lead to extreme hunger right before the period. Spikes in

estrogen Estrogen or oestrogen is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal acti ...

and

progesterone Progesterone (P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the m ...

and decreased

serotonin Serotonin () or 5-hydroxytryptamine (5-HT) is a monoamine neurotransmitter. Its biological function is complex and multifaceted, modulating mood, cognition, reward, learning, memory, and numerous physiological processes such as vomiting and vas ...

can lead to cravings for

carbohydrates In organic chemistry, a carbohydrate () is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1 (as in water) and thus with the empirical formula (where ''m'' may or may ...

and fats. These can be all part of

premenstrual syndrome Premenstrual syndrome (PMS) refers to emotional and physical symptoms that regularly occur in the one to two weeks before the start of each menstrual period. Symptoms resolve around the time menstrual bleeding begins. Different women experienc ...

(PMS). According to the National Center for Biomedical Information, polyphagia is found in the following conditions: * Chromosome 22q13 duplication syndrome * Chromosome 2p25.3 deletion (MYT1L Syndrome) * Chromosome Xq26.3 duplication syndrome * Congenital generalized

lipodystrophy Lipodystrophy syndromes are a group of genetic or acquired disorders in which the body is unable to produce and maintain healthy fat tissue. The medical condition is characterized by abnormal or degenerative conditions of the body's adipose tissue. ...

type 1 * Congenital generalized

type 2 *

Diabetes mellitus type 1 Type 1 diabetes (T1D), formerly known as juvenile diabetes, is an autoimmune disease that originates when cells that make insulin (beta cells) are destroyed by the immune system. Insulin is a hormone required for the cells to use blood sugar f ...

* Familial renal glucosuria *

Frontotemporal dementia Frontotemporal dementia (FTD), or frontotemporal degeneration disease, or frontotemporal neurocognitive disorder, encompasses several types of dementia involving the progressive degeneration of frontal and temporal lobes. FTDs broadly present as ...

ubiquitin Ubiquitin is a small (8.6 kDa) regulatory protein found in most tissues of eukaryotic organisms, i.e., it is found ''ubiquitously''. It was discovered in 1975 by Gideon Goldstein and further characterized throughout the late 1970s and 1980s. Fo ...

-positive *

Hypotonia Hypotonia is a state of low muscle tone (the amount of tension or resistance to stretch in a muscle), often involving reduced muscle strength. Hypotonia is not a specific medical disorder, but a potential manifestation of many different diseases a ...

cystinuria Cystinuria is an inherited autosomal recessive disease characterized by high concentrations of the amino acid cystine in the urine, leading to the formation of cystine stones in the kidneys, ureters, and bladder. It is a type of aminoaciduria. ...

syndrome * Kleine-Levin syndrome *

Leptin Leptin (from Ancient Greek, Greek λεπτός ''leptos'', "thin" or "light" or "small") is a hormone predominantly made by adipose cells and enterocytes in the small intestine that helps to regulate Energy homeostasis, energy balance by inhib ...

deficiency or dysfunction *

Leptin receptor Leptin receptor, also known as LEP-R or OB-R, is a type I cytokine receptor, a protein that in humans is encoded by the ''LEPR'' gene. LEP-R functions as a receptor for the fat cell-specific hormone leptin. LEP-R has also been designated as CD2 ...

deficiency * Luscan-lumish syndrome * Macrosomia adiposa congenita * Mental retardation, autosomal dominant 1 * Obesity, hyperphagia, and developmental delay (OBHD) *

Pick's disease Frontotemporal dementia (FTD), or frontotemporal degeneration disease, or frontotemporal neurocognitive disorder, encompasses several types of dementia involving the progressive degeneration of frontal and temporal lobes. FTDs broadly present as ...

* Prader-Willi syndrome *

Proopiomelanocortin Pro-opiomelanocortin (POMC) is a precursor polypeptide with 241 amino acid residues. POMC is synthesized in corticotrophs of the anterior pituitary from the 267-amino-acid-long polypeptide precursor pre-pro-opiomelanocortin (pre-POMC), by the r ...

deficiency * Schaaf-yang syndrome

Polyphagia in diabetes

Diabetes mellitus causes a disruption in the body's ability to transfer glucose from food into energy. Intake of food causes glucose levels to rise without a corresponding increase in energy, which leads to a persistent sensation of hunger. Polyphagia usually occurs early in the course of

diabetic ketoacidosis Diabetic ketoacidosis (DKA) is a potentially life-threatening complication of diabetes mellitus. Signs and symptoms may include vomiting, abdominal pain, deep gasping breathing, increased urination, weakness, confusion and occasionally loss of ...

. However, once insulin deficiency becomes more severe and ketoacidosis develops, appetite is suppressed.

References

External links

Diseases and conditions associated with Polyphagia
{{Authority control Symptoms and signs: Endocrinology, nutrition, and metabolism

Etymology and pronunciation

Underlying conditions and possible causes

Polyphagia in diabetes

See also

References

External links