Polyphagia or hyperphagia is an abnormally strong,
incessant sensation of
hunger 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 bin ...
. 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 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 bel ...
), 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 (, " ...
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 wi ...
, it is one of the "3 Ps" commonly associated with uncontrolled
diabetes mellitus.
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, 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, it is sometimes termed megaphagia.
Knocking out
vagal nerve receptors has been shown to cause hyperphagia.
Changes in
hormones associated with the female
menstrual cycle 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 ac ...
and
progesterone and decreased
serotonin can lead to cravings for
carbohydrates and
fats. These can be all part of
premenstrual syndrome (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 type 1
* Congenital generalized
lipodystrophy type 2
*
Diabetes mellitus type 1
* Familial
renal glucosuria
*
Frontotemporal dementia
*
Frontotemporal dementia,
ubiquitin-positive
*
Graves' disease
*
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 ...
-
cystinuria syndrome
*
Kleine-Levin syndrome
*
Leptin 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 a ...
*
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 ...
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.
However, once insulin deficiency becomes more severe and ketoacidosis develops, appetite is suppressed.
See also
References
External links
Diseases and conditions associated with Polyphagia
{{Authority control
Symptoms and signs: Endocrinology, nutrition, and metabolism