title: Avicenna's View on Optimal Daily Water Intake.
abstract: BACKGROUND
  Fluid intake is an essential factor in having a normal homeostasis. However, proper amount of daily water intake in a healthy individual is controversial. There is a prevalent thought that we all have to drink eight glasses of water daily, however, it lacks enough supportive evidence at least for healthy individuals. Here, we try to clarify this topic from the perspective of Avicenna and traditional Persian medicine (TPM).
  
  
  METHODS
  The most important traditional Persian medical encyclopedia, Al-Qanun fil-Tibb (Canon of Medicine), was reviewed. Furthermore, Medline, EMBASE, Scopus, IranMedex, and Science Iranian Database (SID) focusing on the keywords "traditional medicine", "water intake", "fluid'', and "complementary and alternative medicine" were reviewed to find relevant information.
  
  
  RESULTS
  Avicenna believed that the demand for daily water is not the same in different individuals. The determinant variables mentioned in his book, The Canon of Medicine, comprises mizaj (temperament), health status, age, sex, season, place, habits, occupation, etc. He believed that water in extra amount quenches the hararat-e-ghariezi, which is the basal internal heat to convey normal homeostasis and metabolism in the body.
  
  
  CONCLUSIONS
  Several factors determine the actual need of any person to drink water. Consequently, recommending a specific amount of daily water intake for all is illogical. Moreover, important recommendations of TPM sages on an appropriate amount of water intake should be considered to prevent associated disorders.
authors.affiliation: Research Center for Traditional Medicine and History of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran; Essence of Parsiyan Wisdom Institute, Traditional Medicine and Medicinal Plant Incubator, Shiraz University of Medical Sciences, Shiraz, Iran; Department of Traditional Persian Medicine, School of Traditional Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Majid
authors.initials: M
authors.lastname: Nimrouzi
authors.affiliation: Research Center for Traditional Medicine and History of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran; Essence of Parsiyan Wisdom Institute, Traditional Medicine and Medicinal Plant Incubator, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Babak
authors.initials: B
authors.lastname: Daneshfard
authors.affiliation: Essence of Parsiyan Wisdom Institute, Traditional Medicine and Medicinal Plant Incubator, Shiraz University of Medical Sciences, Shiraz, Iran; Department of Traditional Persian Medicine, School of Traditional Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Vahid
authors.initials: V
authors.lastname: Tafazoli
keywords: Drinking; Medicine; Traditional; Water-Electrolyte Balance