ADH hormone - Functions, Factors, Mechanism, Disorders and Levels

Antidiuretic Hormone (ADH)

Edited By Irshad Anwar | Updated on Jul 02, 2025 05:09 PM IST

Antidiuretic hormone (ADH), also known as vasopressin, is an important hormone produced by the hypothalamus and released by the posterior pituitary gland. It maintains water balance by increasing water reabsorption in the kidneys. ADH plays a great role in homeostasis, controlling blood volume and osmotic pressure. It is one of the major scoring chapters in biology in CBSE class 11. It accounts for 2-4% of total marks in entrance exams such as NEET, AIIMS, nursing, paramedical, and pharmacy.

This Story also Contains

Synthesis and Storage of Antidiuretic Hormone
Factors Affecting the Regulation of Antidiuretic Hormone
Antidiuretic Hormone Functions
Mechanism of Action Antidiuretic Hormone
Functions of Antidiuretic Hormones
Side Effects Of Antidiuretic Hormones
Antidiuretic Hormonal Disorders
Tips, Tricks, And Strategies To Prepare For ADH Hormone
Types of Questions Asked on Antidiuretic Hormone in Different Exams
Weightage of Antidiuretic Hormone in Different Entrance Exams
Recommended Video On ADH Hormone

Synthesis and Storage of Antidiuretic Hormone

Although the posterior pituitary lobe, or neurohypophysis, does not synthesize hormones, it does store and secrete two peptide hormones, namely oxytocin and vasopressin.

Antidiuretic Hormone is one of the two neurohormones synthesized by the neurosecretory cells present in the hypothalamus and carried to the neurohypophysis along the nerve fibres, where it is stored along with oxytocin.

Specialized neurons of the hypothalamus with the ability to secrete known as “neurosecretory cells,” synthesize these hormones, which are then transported axonally via neurohypophysial capillaries to the posterior lobe.

Thus, the antidiuretic hormone (ADH or vasopressin hormone) is secreted into the bloodstream by the posterior lobe of the pituitary gland present at the base of the brain.

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Factors Affecting the Regulation of Antidiuretic Hormone

The release of Antidiuretic Hormone into the bloodstream is regulated by various factors. These include:

Factors	Antidiuretic Hormone release affects
Blood pressure	It is detected by receptors present in large blood vessels and the heart which increases antidiuretic hormone secretion.
Salt concentration	This is detected by neurosecretory cells present in the hypothalamus and hence results in increasing antidiuretic hormone secretion.
High adh due to medical complications	This can be due to the effects of drugs, pulmonary conditions, and, in severe cases, cancers such as leukaemia and lymphoma.
Alcohol consumption	Restricts the release of ADH. Results in severe dehydration.
High ADH levels	Lower the salt levels and increase water retention in the body. Also dilutes the blood.

Antidiuretic Hormone Functions

Some of the major functions of Antidiuretic Hormone is discussed below:

The antidiuretic hormone causes vasoconstriction and clot formation.
The antidiuretic hormone plays a significant role in regulating the biological clock.
ADH maintains the body's homeostasis, blood volume & the smooth and proper flow of urine from the kidneys.
Apart from this adh also maintains an appropriate volume of water in the spaces surrounding the cells inside the body.
The antidiuretic hormone also aids in smooth cellular functions.

Mechanism of Action Antidiuretic Hormone

The Antidiuretic Hormone mechanism of action can be explained as follows-

Antidiuretic Hormone exerts an antidiuretic action by enhancing the reabsorption of water from the kidneys back into circulation. Antidiuretic or vasopressin affects V1 and V2 receptors to produce its effects.

Aspect	Mechanism
Receptor action	Acts upon V1 and V2 receptors to activate their effects.
V2 receptors	Increases cyclic amp which is responsible for raising water permeability into kidney tubules This increases the overall water reabsorption rate in the body.
V1 receptors	It is stimulated by smooth muscle contraction. This works for the cardiovascular system and kidneys.

Vasopressin Mechanism of Action

Functions of Antidiuretic Hormones

ADH causes constriction of blood vessels and raises blood volume or blood pressure, which is why it is called vasopressin.

Effect of Antidiuretic Hormone	Explanation
Blood vessel constriction	It helps in increasing blood pressure and blood volume, and this results in constriction of the blood vessels.
Contraction of smooth muscles	Helps some contracting smooth muscles of the body such as the small intestine, large intestine, gallbladder, urinary bladder, and blood vessels.
Maintenance of homeostasis	Also helps in the maintenance of body homeostasis and proper cellular functions.
Water reabsorption	Acts upon proximal renal tubules that are responsible for water reabsorption. Also reduces urine volume by concentrating it.
Regulation of the circadian cycle	Antidiuretic hormone maintains the body's circadian cycle by regulating it.

Side Effects Of Antidiuretic Hormones

Excess secretion of Antidiuretic Hormone can also lead to some major side effects in the body. Some of them are mentioned below:

A low level of ADH in the blood results in diabetes insipidus, where the reabsorption of water is reduced.
This results in excessive water loss through dilute urine.
Antidiuretic hormone often lowers blood pressure and increases urine volume.
Hyposecretion of adh also causes damage to the hypothalamus and pituitary gland.
A high adh level causes the blood to dilute and the plasma to be low in sodium.
Hypersecretion of adh can result in acute conditions with symptoms such as nausea, headache, dehydration, vomiting, etc.

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Antidiuretic Hormonal Disorders

A hyper or hypo secretion of ADH often results in several disorders.

These are as follows-

Insomnia
Head injuries
Infertility - Causes and Types of Solutions
Delayed puberty
Frequent urination
Autoimmune disorders
Change in appetite etc.

Tips, Tricks, And Strategies To Prepare For ADH Hormone

Here are some quick tips, tricks, and strategies to remember the role of ADH (antidiuretic hormone) or vasopressin:

"Anti-diuretic" = Less Uretic

"Anti" means opposing, so ADH reduces urination by retaining water in the body.

Vasopressin = Vessel Pressure

Vasopressin is another name for ADH. It presses the blood vessels, leading to an increase in blood pressure.
Remember: Vasopressin = Vessel pressure rises.

V2 = Water Reabsorption

V2 receptors in the kidneys help in water reabsorption.
Tip: Think of H2O to remember V2's role with water.

V2 = Very Thirsty

When ADH acts on the kidneys, water is reabsorbed, reducing thirst and maintaining hydration.

Types of Questions Asked on Antidiuretic Hormone in Different Exams

During preparation for different exams, students may face different questions on the topic of antidiuretic hormone

Exam type	Types of questions asked
CBSE	Definition of Antidiuretic hormones, explanation of their role, effects of adh on blood pressure, and difference between adh and other hormones.
NEET	Mechanism of action of Antidiuretic hormone, implications of Antidiuretic hormones, case studies related to Antidiureutic hormones disorder.
Paramedical Entrance Exams	Managing the disorders.

Weightage of Antidiuretic Hormone in Different Entrance Exams

The table which is given below contains the overall weightage of the topic of antidiuretic hormone in different exams. This will help in increasing concentration on the topic as per the weightage.

Entrance Exam	Weightage (Approximate)
NEET (National Eligibility cum Entrance Test)	1-2 Questions
AIIMS (All India Institute of Medical Sciences)	1-2 Questions
JIPMER (Jawaharlal Institute of Postgraduate Medical Education and Research)	1 Question
PGIMER (Postgraduate Institute of Medical Education and Research)	2-3 Questions
KVPY (Kishore Vaigyanik Protsahan Yojana)	0-1 Question
ICMR JRF (Indian Council of Medical Research Junior Research Fellowship)	1-2 Questions
GATE (Life Sciences)	1 Question
AIAPGET (All India AYUSH Post Graduate Entrance Test)	1 Question

Conclusion

As we have gone through the details of antidiuretic hormone, its action, its regulatory pathway, and clinical significance it becomes important for us to understand why it is important for our body.

It is essential to recognize the implications for our health homeostasis and also the various physiological effects of ADH on our body. This is one of the underrated integrated relationships between our hormones and overall health.

Also Read:

Hormones	Thyroid Gland
Mechanism of hormone action	Parathyroid Gland
Hormone receptors	Hyperparathyroidism
Thymus Gland	Adrenal Gland

Recommended Video On ADH Hormone

Frequently Asked Questions (FAQs)

1. What is the full form of ADH? List alternative names for it.

ADH full form in medical science reads for antidiuretic hormone. This naturally occurring nonapeptide hormone is also termed vasopressin hormone, arginine vasopressin (AVP), or pitressin.

2. Why is the Vasopressin hormone called ADH?

Vasopressin hormone is also called ADH because it is effective against diuresis. (a medical condition of excessive urine production)

3. Where does the synthesis of ADH take place?

The synthesis of ADH takes place in the supraoptic and paraventricular nuclei present in the hypothalamus, not in the posterior pituitary.

4. Why is ADH called Vasopressin?

Since ADH causes constriction of blood vessels, it is also called vasopressin.

5. What do you mean by diabetes insipidus?

A low level of antidiuretic hormone in the blood refers to Diabetes insipidus where reabsorption of water gets reduced resulting in excessive water loss through dilute urine. This often lowers blood pressure and increases urine volume.

6. What is Antidiuretic Hormone and its function?

Antidiuretic hormone is secreted by the hypothalamus present in the brain whereas it is stored in the posterior pituitary gland. It is one of the important hormones that helps in regulating electrolyte balance, water balance concentration of urine blood pressure, and also regulates the water reabsorption rate in kidneys.

7. What is diabetes insipidus and how is it related to ADH?

Diabetes insipidus is a condition characterized by excessive thirst and urination. It can be caused by either insufficient ADH production (central diabetes insipidus) or kidney insensitivity to ADH (nephrogenic diabetes insipidus). In both cases, the body cannot properly regulate water reabsorption.

8. What happens if there's an overproduction of ADH?

Overproduction of ADH, known as Syndrome of Inappropriate ADH Secretion (SIADH), can lead to excessive water retention and dilution of blood sodium levels (hyponatremia). This can cause symptoms such as headache, nausea, confusion, and in severe cases, seizures or coma.

9. How do certain medications affect ADH function?

Some medications can interfere with ADH function. For example, lithium can cause nephrogenic diabetes insipidus by making the kidneys less responsive to ADH. Conversely, certain drugs like desmopressin act as ADH analogs, mimicking its effects on the kidneys.

10. How does chronic dehydration affect ADH levels?

Chronic dehydration can lead to persistently elevated ADH levels as the body tries to conserve water. Over time, this can lead to increased thirst, reduced urine output, and potentially more concentrated blood (if water intake remains insufficient).

11. How does ADH secretion change with age?

ADH secretion and kidney responsiveness to ADH can decrease with age. This can lead to increased nighttime urination (nocturia) in older adults and a higher risk of dehydration. However, the extent of these changes varies among individuals.

12. What is the role of ADH in blood volume regulation during hemorrhage?

During hemorrhage, the decrease in blood volume triggers increased ADH secretion. This helps conserve water by increasing reabsorption in the kidneys and causes vasoconstriction to help maintain blood pressure despite the reduced blood volume.

13. What is the relationship between ADH and blood pressure regulation?

ADH contributes to blood pressure regulation in two ways: 1) by promoting water retention, which increases blood volume, and 2) by causing vasoconstriction. Both of these effects can help increase or maintain blood pressure, especially in situations of low blood volume or pressure.

14. What is the role of ADH in adaptation to high altitude?

At high altitudes, the body increases ADH secretion as part of its adaptation process. This helps combat the increased fluid loss through respiration and sweating that occurs at high altitudes, helping to maintain proper hydration and blood volume.

15. What role does ADH play in the sensation of thirst?

While ADH doesn't directly cause thirst, its release is often coincident with thirst sensation. Both are triggered by similar stimuli, such as increased blood osmolarity. ADH acts to conserve water internally, while thirst drives water-seeking behavior.

16. What is the relationship between ADH and urea in urine concentration?

ADH enhances urea reabsorption in the inner medullary collecting ducts. This helps maintain a high osmotic gradient in the kidney medulla, which is crucial for concentrating urine. The interplay between ADH and urea contributes to the kidney's ability to produce concentrated urine.

17. What triggers the release of ADH?

ADH release is primarily triggered by an increase in blood osmolarity (concentration of solutes) or a decrease in blood volume. These changes are detected by osmoreceptors in the hypothalamus and baroreceptors in blood vessels, respectively.

18. Can excessive water intake affect ADH levels?

Yes, excessive water intake can suppress ADH secretion. When blood becomes diluted (hyponatremia), it signals the body to reduce ADH production, leading to increased urine output to eliminate excess water and maintain proper blood osmolarity.

19. How does alcohol consumption affect ADH secretion?

Alcohol inhibits ADH secretion from the posterior pituitary gland. This leads to increased urine production (diuresis) and can contribute to dehydration, which is why drinking alcohol often makes people urinate more frequently and feel thirsty.

20. How does ADH secretion change during sleep?

ADH secretion typically increases during sleep, especially at night. This nocturnal rise in ADH helps reduce urine production overnight, allowing for uninterrupted sleep. This is why urine is often more concentrated in the morning.

21. What is the connection between ADH and blood sodium levels?

ADH secretion is closely linked to blood sodium levels. High sodium concentrations (hypernatremia) stimulate ADH release, promoting water retention to dilute the blood. Conversely, low sodium levels (hyponatremia) suppress ADH secretion to prevent further dilution of the blood.

22. How does ADH contribute to maintaining blood pressure?

ADH helps maintain blood pressure in two ways: 1) by increasing water reabsorption in the kidneys, which increases blood volume, and 2) by causing vasoconstriction (narrowing of blood vessels), which directly increases blood pressure.

23. How does ADH affect blood vessel tone?

ADH causes vasoconstriction (narrowing of blood vessels) by binding to V1 receptors on vascular smooth muscle cells. This effect is particularly pronounced in situations of severe blood loss or shock, where it helps maintain blood pressure.

24. What is the relationship between ADH and thirst?

ADH and thirst are both triggered by similar stimuli, such as increased blood osmolarity. When ADH is released, it often coincides with the sensation of thirst. This dual response helps to both conserve existing water and encourage water intake to maintain proper hydration.

25. What is the difference between ADH and aldosterone in kidney function?

While both hormones affect kidney function, ADH primarily regulates water reabsorption, whereas aldosterone regulates sodium reabsorption and potassium excretion. ADH acts on the collecting ducts, while aldosterone acts on the distal tubules and collecting ducts.

26. What role does ADH play in thermoregulation?

ADH contributes to thermoregulation indirectly by helping maintain proper hydration. Adequate hydration is crucial for effective sweating, which is an important mechanism for cooling the body. Additionally, ADH's vasoconstrictive effects can help conserve heat in cold environments.

27. How does ADH affect water reabsorption in the kidneys?

ADH increases water reabsorption in the kidneys by making the collecting ducts more permeable to water. It does this by stimulating the insertion of aquaporin water channels into the cell membranes of the collecting duct cells, allowing more water to be reabsorbed into the bloodstream.

28. How do the kidneys respond to ADH at the cellular level?

When ADH binds to its receptors on collecting duct cells, it triggers a signaling cascade that results in the insertion of aquaporin-2 water channels into the cell membrane. This increases the permeability of the cells to water, allowing more water to be reabsorbed from the urine into the bloodstream.

29. How does ADH affect urine concentration?

ADH increases urine concentration by promoting water reabsorption in the collecting ducts. This results in a smaller volume of more concentrated urine. Without ADH, the urine would be more dilute and greater in volume.

30. How do aquaporins facilitate ADH's effects on water reabsorption?

Aquaporins are water channel proteins that allow rapid movement of water across cell membranes. ADH stimulates the insertion of aquaporin-2 channels into the apical membrane of collecting duct cells, creating a pathway for water to move from the tubule lumen into the cells and eventually into the bloodstream.

31. What is the relationship between ADH and blood osmolarity?

There is a direct relationship between blood osmolarity and ADH secretion. As blood osmolarity increases (becomes more concentrated), ADH secretion increases to promote water retention and dilute the blood back to normal levels.

32. How does chronic kidney disease affect ADH function and water balance?

Chronic kidney disease can impair the kidney's ability to respond to ADH, leading to difficulties in concentrating urine. This can result in increased urine output and a tendency towards dehydration. In advanced stages, the diseased kidneys may also affect the feedback mechanisms that regulate ADH secretion.

33. How does salt intake affect ADH secretion?

High salt intake can stimulate ADH secretion by increasing blood osmolarity. This triggers the release of ADH to promote water retention, helping to dilute the increased sodium concentration in the blood. Conversely, low salt intake can lead to decreased ADH secretion.

34. What is the role of ADH in thermoregulation during fever?

During fever, ADH levels often increase. This helps conserve water as the body's temperature rises, counteracting the increased fluid loss through sweating and respiration. The water-retaining effect of ADH helps maintain proper hydration during the fever response.

35. What is Antidiuretic Hormone (ADH) and where is it produced?

Antidiuretic Hormone (ADH), also known as vasopressin, is a hormone produced in the hypothalamus and stored in the posterior pituitary gland. It plays a crucial role in regulating water balance in the body by controlling water reabsorption in the kidneys.

36. What is the role of ADH in osmoregulation in different animal species?

While the specific mechanisms may vary, ADH or its analogs play a crucial role in osmoregulation across many animal species. In fish, for example, arginine vasotocin (AVT) serves a similar function to ADH in terrestrial vertebrates, helping regulate water and ion balance in different aquatic environments.

37. How do certain diseases affect ADH function or secretion?

Various diseases can affect ADH function or secretion. For example, some cancers can cause SIADH, leading to excessive ADH secretion. Kidney diseases can affect the organ's response to ADH. Brain injuries or tumors affecting the hypothalamus or pituitary can disrupt ADH production.

38. What is the relationship between ADH and urine specific gravity?

ADH increases urine specific gravity by promoting water reabsorption in the kidneys. This results in more concentrated urine with a higher specific gravity. In conditions where ADH is absent or ineffective, urine specific gravity tends to be lower due to the production of more dilute urine.

39. What is the relationship between ADH and the concentration of other electrolytes besides sodium?

While ADH primarily affects water balance and indirectly sodium concentration, it can influence the concentration of other electrolytes. By altering the amount of water in the blood and urine, ADH can affect the relative concentrations of electrolytes like potassium, chloride, and calcium.

40. What is the relationship between ADH and nocturnal enuresis (bedwetting)?

Some cases of nocturnal enuresis in children have been associated with an insufficient nighttime increase in ADH secretion. Normally, ADH levels rise at night to reduce urine production during sleep. When this rise is inadequate, it can lead to overproduction of urine at night and potentially bedwetting.

41. How does ADH affect potassium balance in the body?

While ADH primarily regulates water balance, it can indirectly affect potassium balance. By promoting water reabsorption, ADH can influence the concentration of potassium in the urine and blood. However, other hormones like aldosterone play a more direct role in potassium regulation.

42. How does ADH secretion change during pregnancy?

ADH levels typically increase during pregnancy. This helps the mother's body retain more water to support the increased blood volume needed during pregnancy. However, excessive ADH can sometimes lead to water retention and hyponatremia.

43. What is the difference between central and nephrogenic diabetes insipidus?

Central diabetes insipidus is caused by insufficient ADH production in the brain, while nephrogenic diabetes insipidus is caused by the kidneys' inability to respond properly to ADH. Both result in excessive urine production, but the underlying mechanisms and treatments differ.

44. Can ADH secretion be influenced by circadian rhythms?

Yes, ADH secretion follows a circadian rhythm, with levels typically higher at night. This nocturnal increase helps reduce urine production during sleep. Disruptions to this rhythm, such as in shift work or jet lag, can affect ADH secretion and urination patterns.

45. How quickly can ADH levels change in response to stimuli?

ADH levels can change rapidly in response to stimuli, with significant increases occurring within minutes of a trigger such as increased blood osmolarity or decreased blood volume. This quick response allows for rapid adjustments in water balance.

46. How does ADH interact with the renin-angiotensin-aldosterone system (RAAS)?

ADH and the RAAS work together to regulate blood pressure and fluid balance. While ADH primarily affects water reabsorption, the RAAS influences sodium retention and blood vessel constriction. Both systems are activated by low blood volume or pressure.

47. What is the half-life of ADH in the bloodstream?

The half-life of ADH in the bloodstream is relatively short, typically around 15-20 minutes. This allows for rapid adjustments in water balance as the body's needs change throughout the day.

48. What is the evolutionary significance of ADH?

ADH plays a crucial role in water conservation, which is essential for survival, especially in environments where water is scarce. The ability to concentrate urine and retain water allowed animals to adapt to terrestrial life and survive in diverse habitats.

49. Can ADH levels be measured clinically, and if so, how?

Yes, ADH levels can be measured clinically through blood tests. However, due to ADH's short half-life and instability, it's more common to measure copeptin, a stable peptide that's released in equimolar amounts with ADH. Urine osmolality is also often used as an indirect measure of ADH activity.

50. Can stress influence ADH secretion?

Yes, stress can stimulate ADH secretion. The stress response activates the hypothalamic-pituitary-adrenal (HPA) axis, which can lead to increased ADH release. This may contribute to the dry mouth often experienced during stressful situations.

51. How does ADH contribute to the countercurrent multiplication system in the kidneys?

ADH enhances the countercurrent multiplication system by increasing water reabsorption in the collecting ducts. This helps maintain the osmotic gradient in the medulla of the kidney, which is crucial for the concentration of urine.

52. How does ADH interact with other hormones involved in fluid balance?

ADH works in concert with other hormones like aldosterone, atrial natriuretic peptide (ANP), and renin-angiotensin to maintain fluid balance. While ADH primarily regulates water retention, these other hormones influence sodium balance, which indirectly affects water balance.

53. How does ADH contribute to the body's response to dehydration?

During dehydration, ADH secretion increases significantly. This prompts the kidneys to reabsorb more water, reducing urine output and concentrating the urine. ADH also stimulates thirst, encouraging water intake. These combined effects help restore normal hydration status.

54. How does ADH secretion change during exercise?

During exercise, ADH secretion typically increases. This helps prevent dehydration by promoting water retention in the kidneys. The increase in ADH is part of the body's overall response to the fluid loss and increased metabolic demands associated with physical activity.

55. How does ADH contribute to the maintenance of cell volume?

ADH plays a crucial role in maintaining cell volume by regulating extracellular fluid osmolarity. By controlling water reabsorption in the kidneys, ADH helps maintain a stable osmotic environment for cells, preventing excessive shrinkage or swelling due to osmotic shifts.

56. How does ADH contribute to the body's adaptation to different environmental conditions?

ADH plays a key role in adapting to various environmental conditions by regulating water balance. In hot, dry environments, increased ADH helps conserve water. In cold environments, ADH's vasoconstrictive effects can help maintain core body temperature. This adaptability has been crucial in allowing humans and other animals to survive in diverse habitats.