thirst

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thirst

physiology

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July 14, 2026

Quick Summary

Thirst is a physiological sensation that signals the body's need for water. It is triggered when the body loses fluids, leading to a decrease in plasma volume and an increase in the concentration of solutes in the blood. This change is detected by the brain's thirst center, located in the hypothalamus.12

When dehydrated, the body conserves water by reducing urine output and increasing thirst. This sensation prompts fluid intake, which is essential for maintaining bodily functions. Water is crucial for transporting nutrients, regulating body temperature, lubricating joints, and aiding digestion.3

A rare disorder called adipsia is characterized by a lack of thirst, even when dehydrated. This condition results from damage to the hypothalamus and requires individuals to be instructed to drink fluids regularly to prevent severe dehydration. Dehydration itself can lead to various symptoms, including dry mouth, sunken eyes, confusion, and in severe cases, can be fatal.145

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adipsia
…characterized by the lack of thirst even in the presence of dehydration. In adipsia the brain’s thirst centre, located in the hypothalamus, is damaged. People with adipsia have little or no sensation of thirst when they become dehydrated. These people must be instructed, even forced, to drink fluid at regular…
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…characterized by the lack of thirst even in the presence of dehydration. In adipsia the brain’s thirst centre, located in the hypothalamus, is damaged. People with adipsia have little or no sensation of thirst when they become dehydrated. These people must be instructed, even forced, to drink fluid at regular…
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human sensory reception
…such experiences as hunger and thirst. Some brain cells may also participate as hunger receptors. This is especially true of cells in the lower parts of the brain (such as the hypothalamus) where some cells have been found to be sensitive to changes in blood chemistry (water and other products…
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…such experiences as hunger and thirst. Some brain cells may also participate as hunger receptors. This is especially true of cells in the lower parts of the brain (such as the hypothalamus) where some cells have been found to be sensitive to changes in blood chemistry (water and other products…
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forebrain
drive, pleasure, pain, hunger, thirst, blood pressure, body temperature, and other visceral functions. The hypothalamus produces hormones that control the secretions of the anterior pituitary gland, and it also produces oxytocin and antidiuretic hormone, which are stored in and released by the posterior pituitary gland.
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drive, pleasure, pain, hunger, thirst, blood pressure, body temperature, and other visceral functions. The hypothalamus produces hormones that control the secretions of the anterior pituitary gland, and it also produces oxytocin and antidiuretic hormone, which are stored in and released by the posterior pituitary gland.
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dehydration
Symptoms and progression
This results in the thirst that always accompanies “pure” water depletion.
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This results in the thirst that always accompanies “pure” water depletion.
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