Document Type : Review Article


1 Department of Physiology, Arsanjan Branch, Islamic Azad University, Fars, Iran

2 Department of Nursing, Arsanjan Branch, Islamic Azad University, Fars, Iran


 Fluid balance is essential for life. Some studies have shown an association between high intake of water and a low risk of cardiovascular diseases. However, the evidence is insufficient or inconsistent to draw substantial conclusions. The author's objective was to review previous studies addressing the influence of drinking water and hydration status on the cardiovascular system. The PubMed and Google Scholar databases were searched using relevant terms. Animal and human studies in the English language which were highly relevant to the topic were selected and summarized. Drinking about half a liter of water rapidly raises sympathetic activity as much as classic sympathetic stimuli such as caffeine and increases plasma norepinephrine leading to peripheral vasoconstriction. However, cardiac vagal tone enhancement with water ingestion buffers the pressor effects of sympathetic activation. Dehydration leads to mild hypernatremia which gradually causes changes such as increased blood viscosity, hemoconcentration, inflammatory signals, platelet activation and aggregation, adhesive properties of endothelial cells, thrombogenesis, and so on, all of which are harmful to the cardiovascular system. Overhydration can result in water intoxication and increase coagulability. Both dehydration and overhydration are associated with several adverse effects on the cardiovascular system. However, the data regarding how much water can reduce the risk of heart disease is limited and the results are also controversial. More research is needed to confirm the observed associations between hydration status and cardiovascular diseases.


  1. El-Sharkawy AM, Sahota O, Lobo DN. Acute and chronic effects of hydration status on health. Nutrition Reviews. 2015;73 2, 97-109.
  2. Jequier E, Constant F. Water as an essential nutrient: the physiological basis of hydration. European Journal of Clinical Nutrition. 2010;64, 115-123.
  3. Chan J, Knutsen SF, Blix, GG, Lee, JW, Fraser GE. Water, other fluids, and fatal coronary heart disease: the Adventist Health Study. American Journal of Epidemiology. 2002;155, 827-833.
  4. Manz F, Wentz A. The importance of good hydration for the prevention of chronic diseases. Nutrition Reviews. 2005;63, S2-5.
  5. Ruttmann TG, Jamest MF, Lombard EH. Haemodilution-induced enhancement of coagulation is attenuated in vitro by restoring antithrombin III to pre-dilution concentrations. Anaesthesia and Intensive care. 2001;29, 489-493.
  6. Brown CM, Barberini L, Dulloo AG, Montani J P. Cardiovascular responses to water drinking: does osmolality play a role? American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. 2005289, R1687-1692.
  7. Routledge HC, Chowdhary S, Coote JH, Townend JN. Cardiac vagal response to water ingestion in normal human subjects. Clinical Science. 2002;103, 157-162.
  8. Jordan J, Shannon JR, Black BK, Ali Y, Farley M, Costa F, Diedrich A, Robertson RM, Biaggioni I, Robertson D. The pressor response to water drinking in humans: a sympathetic reflex? Circulation. 2000101, 504-509
  9. Scott EM, Greenwood JP, Gilbey SG, Stoker JB, Mary DA. Water ingestion increases sympathetic vasoconstrictor discharge in normal human subjects. Clinical Science. 2001;100, 335-342.
  10. Monnard CR, Grasser EK. Water ingestion decreases cardiac workload time-dependent in healthy adults with no effect of gender. Scientific Reports. 2017;7, 7939.
  11. Lu CC, Li MH, Lin TC, Chen TL, Chen RM, Tung CS, Tseng CJ, Ho ST. Water ingestion reduces skin blood flow through sympathetic vasoconstriction. Clinical Autonomic Research. 2012;22, 63-69.
  12. Rossi P, Andriesse GI, Oey PL, Wieneke GH, Roelofs JM, Akkermans LM. Stomach distension increases efferent muscle sympathetic nerve activity and blood pressure in healthy humans. Journal of the Neurological Sciences. 1998;161, 148-155.
  13. Girona M, Grasser EK, Dulloo AG, Montani JP. Cardiovascular and metabolic responses to tap water ingestion in young humans: does the water temperature matter? Acta Physiologica. 2014;211, 358-370.
  14. van Orshoven NP, Oey PL, van Schelven LJ, Roelofs JM, Jansen PA, Akkermans LM. Effect of gastric distension on cardiovascular parameters: gastrovascular reflex is attenuated in the elderly. The Journal of Physiology. 2004555, 573-583.
  15. Nakai, M. Cardiovascular responses to gastric hypo-osmolar stimulation in anesthetized dogs. The Japanese Journal of Physiology. 1993;43, 335-346.
  16. Osaka T, Kobayashi A, Inoue S. Thermogenesis induced by osmotic stimulation of the intestines in the rat. The Journal of physiology. 2001;532, 261-269.
  17. Villanova N, Azpiroz F, Malagelada JR. Perception and gut reflexes induced by stimulation of gastrointestinal thermoreceptors in humans. The Journal of Physiology. 1997;502 (1), 215-222.
  18. Zhang L, Jones S, Brody K, Costa M, Brookes SJ. Thermosensitive transient receptor potential channels in vagal afferent neurons of the mouse. American journal of physiology. Gastrointestinal and Liver Physiology. 2004;286, G983-991.
  19. Guler AD, Lee H, Iida T, Shimizu I, Tominaga M, Caterina M. Heat-evoked activation of the ion channel, TRPV4. The Journal of Neuroscience: The Official Journal of the Society for Neuroscience. 2002;22, 6408-6414.
  20. Bekkevold CM, Robertson KL, Reinhard MK, Battles AH, Rowland NE. Dehydration parameters and standards for laboratory mice. Journal of the American Association for Laboratory Animal Science: JAALAS. 2013;52, 233-239.
  21. Phillips PA, Rolls BJ, Ledingham JG, Forsling ML, Morton JJ, Crowe MJ, Wollner L. Reduced thirst after water deprivation in healthy elderly men. The New England Journal of Medicine. 1984;311, 753-759.
  22. Holbein WW, Toney GM. Sympathetic network drive during water deprivation does not increase respiratory or cardiac rhythmic sympathetic nerve activity. Journal of Applied Physiology. 2013;114, 1689-1696.
  23. Stocker SD, Simmons JR, Stornetta RL, Toney GM, Guyenet PG. Water deprivation activates a glutamatergic projection from the hypothalamic paraventricular nucleus to the rostral ventrolateral medulla. The Journal of Comparative Neurology. 2006;494, 673-685.
  24. Holbein WW, Bardgett ME, Toney GM. Blood pressure is maintained during dehydration by hypothalamic paraventricular nucleus-driven tonic sympathetic nerve activity. The Journal of Physiology. 2014;592, 3783-3799.
  25. Colombari DS, Colombari E, Freiria-Oliveira AH, Antunes VR, Yao ST, Hindmarch C, Ferguson AV, Fry M, Murphy D, Paton JF. Switching control of sympathetic activity from forebrain to hindbrain in chronic dehydration. The Journal of Physiology. 2011589, 4457-4471.
  26. Stocker SD, Hunwick KJ, Toney GM. Hypothalamic paraventricular nucleus differentially supports lumbar and renal sympathetic outflow in water-deprived rats. The Journal of Physiology. 2005; 563, 249-263.
  27. Arnhold MM, Yoder JM, Engeland WC. Subdiaphragmatic vagotomy prevents drinking-induced reduction in plasma corticosterone in water-restricted rats. Endocrinology 2009;150, 2300-2307.
  28. Stocker SD, Stricker EM, Sved AF. Arterial baroreceptors mediate the inhibitory effect of acute increases in arterial blood pressure on thirst. American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. 2002;282, R1718-1729.
  29. Burnier M, Biollaz J, Brunner DB, Brunner HR. Blood pressure maintenance in awake dehydrated rats: renin, vasopressin, and sympathetic activity. The American Journal of Physiology. 1983;245, H203-209.
  30. Breidert M, Bornstein SR, Ehrhart-Bornstein M, Scherbaum WA, Holst JJ. Angiotensin II regulates both adrenocortical and adrenomedullary function in isolated perfused pig adrenals. Peptides. 1996;17, 287-292
  31. Ali MA, Kazzam E, Amir N, Nyberg F, Adem A. Effects of dehydration and blockade of angiotensin II AT1 receptor on stress hormones and anti-oxidants in the one-humped camel. BMC Veterinary Research. 2013;9, 232.
  32. Chrousos GP, Gold PW. A healthy body in a healthy mind--and vice versa--the damaging power of "uncontrollable" stress. The Journal of Clinical Endocrinology and Metabolism. 1998;83, 1842-1845.
  33. Whitworth, J. A., Williamson, P. M., Mangos, G., and Kelly, J. J. (2005) Cardiovascular consequences of cortisol excess. Vascular health and risk management 1, 291-299.
  34. Olsson K, Carlsson E. Cardiovascular changes associated with dehydration and drinking in unrestrained, lactating goats. Experimental Physiology. 1999;84, 571-578.
  35. Tanira MO, el-Sabban FF, Fahim MA, Wasfi IA. Acetyl salicylic acid alleviates increased susceptibility to thrombosis in pial microvessels of dehydrated mice. The Journal of Veterinary Medical Science. 1994;56, 245-248.
  36. Wandersee NJ, Punzalan RC, Rettig MP, Kennedy MD, Pajewski NM, Sabina RL, Paul Scott J, Low PS, Hillery CA. Erythrocyte adhesion is modified by alterations in cellular tonicity and volume. British Journal of Haematology. 2005;131, 366-377.
  37. Kelly J, Hunt BJ, Lewis RR, Swaminathan R, Moody A, Seed PT, Rudd A. Dehydration and venous thromboembolism after acute stroke. QJM: Monthly Journal of the Association of Physicians. 200497, 293-296.
  38. King MA, Clanton TL, Laitano O. Hyperthermia, dehydration, and osmotic stress: unconventional sources of exercise-induced reactive oxygen species. American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. 2016;310, R105-114.
  39. Thornton, S. N. Thirst and hydration: physiology and consequences of dysfunction. Physiology & Behavior. 2010;100, 15-21.
  40. Jaber L, Habre A, Rawda N, Said MA, Barbour E, Hamadeh S. The effect of water restriction on certain physiological parameters in Awassi sheep. Small Ruminant Research. 2004;54, 115-120.
  41. Alamer MA, Ahmed AS. Effect of short-term water restriction in hot season on some blood parameters and immune response to Newcastle disease vaccine of local and commercial layers in the late phase of production. Journal of Animal Physiology and Animal Nutrition. 2012;96, 717-724.
  42. Vosooghi-Postindoz V, Tahmasbi AM, Naserian AA, Valizadeh R, Ebrahimi SH. The effect of intermittent watering on performance, blood metabolites, and nutrient digestibility in Baluchi lambs. Asian-Australasian Journal of Animal Sciences. 2018-3.
  43. Heiderstadt KM, McLaughlin RM, Wright DC, Walker SE, Gomez-Sanchez CE. The effect of chronic food and water restriction on open-field behaviour and serum corticosterone levels in rats. Laboratory Animals. 2000;34, 20-28.
  44. Gray GD, Bergfors AM, Levin R, Levine S. Comparison of the effects of restricted morning or evening water intake on adrenocortical activity in female rats. Neuroendocrinology. 1978;25, 236-246.
  45. Johnson JT, Levine S. Influence of water deprivation on adrenocortical rhythms. Neuroendocrinology. 1973;11, 268-273.
  46. Perrier E, Vergne S, Klein A, Poupin M, Rondeau P, Le Bellego L, Armstrong LE, Lang F, Stookey J, Tack I. Hydration biomarkers in free-living adults with different levels of habitual fluid consumption. The British Journal of Nutrition. 2013;109, 1678-1687.
  47. Choukroun G, Schmitt F, Martinez F, Drueke TB, Bankir L. Low urine flow reduces the capacity to excrete a sodium load in humans. The American Journal of Physiology. 1997;273, R1726-1733.
  48. Nicco C, Wittner M, DiStefano A, Jounier S, Bankir L, Bouby N. Chronic exposure to vasopressin upregulates ENaC and sodium transport in the rat renal collecting duct and lung. Hypertension. 2001;38, 1143-1149.
  49. Coutry N, Farman N, Bonvalet JP, Blot-Chabaud M. Synergistic action of vasopressin and aldosterone on basolateral Na(+)-K(+)-ATPase in the cortical collecting duct. The Journal of Membrane Biology. 1995;145, 99-106.
  50. Bouby N, Fernandes S. Mild dehydration, vasopressin and the kidney: animal and human studies. European Journal of Clinical Nutrition. 2003;57 Suppl 2, S39-46.
  51. Valtin H. "Drink at least eight glasses of water a day." Really? Is there scientific evidence for "8 x 8"? American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. 2002;283, R993-1004.
  52. Dmitrieva NI, Burg MB. Secretion of von Willebrand factor by endothelial cells links sodium to hypercoagulability and thrombosis. Proceedings of the National Academy of Sciences of the United States of America 2014;111, 6485-6490.
  53. Dmitrieva NI, Burg MB. Elevated sodium and dehydration stimulate inflammatory signaling in endothelial cells and promote atherosclerosis. PloS One. 2015;10, e0128870.
  54. Libby P, Ridker PM, Hansson, GK. Progress and challenges in translating the biology of atherosclerosis. Nature. 2011473, 317-325.
  55. Wiman B, Andersson T, Hallqvist J, Reuterwall C, Ahlbom A, deFaire U. Plasma levels of tissue plasminogen activator/plasminogen activator inhibitor-1 complex and von Willebrand factor are significant risk markers for recurrent myocardial infarction in the Stockholm Heart Epidemiology Program (SHEEP) study. Arteriosclerosis, Thrombosis, and Vascular Biology. 2000;20, 2019-2023.
  56. Nussey SS, Bevan DH, Ang VT, Jenkins JS. Effects of arginine vasopressin (AVP) infusions on circulating concentrations of platelet AVP, factor VIII: C and von Willebrand factor. Thrombosis and Haemostasis. 1986;55, 34-36.
  57. Orlowski S, Flees J, Anthony N, Dridi S. Differential expression of water channel- and noncoding RNA biogenesis-related genes in three lines of chickens under a short-term water restriction. Poultry Science. 2017;96, 4172-4181.
  58. Netti V, Iovane A, Zotta E, Fellet A, Balaszczuk A. 6b.06: Cardiac Aqp1 nitrosylation in response to osmotic stress induced by water restriction during postnatal growth. Journal of Hypertension. 2015;33 Suppl 1, e77.
  59. Netti VA, Vatrella MC, Chamorro MF, Roson MI, Zotta E, Fellet AL, Balaszczuk AM. Comparison of cardiovascular aquaporin-1 changes during water restriction between 25- and 50-day-old rats. European Journal of Nutrition. 2014;53, 287-295;
  60. Herrera M, Hong NJ, Garvin JL. Aquaporin-1 transports NO across cell membranes. Hypertension. 2006;48, 157-164.
  61. Gardner JW. Death by water intoxication. Military Medicine. 2002;167, 432-434.
  62. Ferrier IN. Water intoxication in patients with psychiatric illness. British Medical Journal. 1985;291, 1594-1596.
  63. Garigan TP, Ristedt DE. Death from hyponatremia as a result of acute water intoxication in an Army basic trainee. Military Medicine. 1999;164, 234-238.
  64. O'Brien KK, Montain SJ, Corr WP, Sawka MN, Knapik JJ, Craig SC. () Hyponatremia associated with overhydration in U.S. Army trainees. Military Medicine. 2001;166, 405-410.
  65. Baggott MJ, Garrison KJ, Coyle JR, Galloway GP, Barnes AJ, Huestis MA, Mendelson JE. MDMA impairs response to water intake in healthy volunteers. Advances in Pharmacological Sciences. 2016, 2175896.
  66. Stoneham MD, Hill, EL. Variability in post-operative fluid and electrolyte prescription. The British Journal of Clinical Practice. 1997;51, 82-84.