Thirst

thumb|Thirst (1886), by William-Adolphe Bouguereau Thirst is the craving for potable fluids, resulting in the basic instinct of animals to drink. It is an essential mechanism involved in fluid balance. It arises from a lack of fluids or an increase in the concentration of certain osmolites, such as sodium. If the water volume of the body falls below a certain threshold or the osmolite concentration becomes too high, structures in the brain detect changes in blood constituents and signal thirst.

human disease, a condition characterized by large amounts of dilute urine and increased thirst

Polydipsia is excessive thirst or excess drinking. The word derives , which is derived . Polydipsia is a nonspecific symptom in various medical disorders. It also occurs as an abnormal behaviour in some non-human animals, such as in birds.

dry mouth and excessive fluid consumption in the absence of physiological stimuli to drink with physiological suppression of arginine-vasopressin secretion or a decrease in the sensitivity threshold of osmoreceptors (thirst center)

Adipsia, also known as hypodipsia, is a symptom of inappropriately decreased or absent feelings of thirst. It involves an increased osmolality or concentration of solute in the urine, which stimulates secretion of antidiuretic hormone (ADH) from the hypothalamus to the kidneys. This causes the person to retain water and ultimately become unable to feel thirst. Due to its rarity, the disorder has not been the subject of many research studies.

diagnostic method in medicine