Do we sleep, slumber, siesta, or snooze too much?

Who knew that a ‘golden age’ of Arabic/Islamic scholars existed from the ninth to the twelfth centuries in sleep analysis? Five prominent scholar physicians delved where few had gone before and made discoveries that have proven remarkably accurate with the passage of time.
Ahmed S Bahammam, an academic at the University Sleep Disorders Center of King Saud University in Riyadh, Saudi Arabia, has completed research entitled ‘How Golden Age Arab-Islamic Scholars Revolutionised Sleep Physiology and Dream Analysis.’ Not the catchiest of titles, but not least because we spend, according to Mathew Tucker (2025), “a third of our lives sleeping,” it tempted me... The Arabic/Islamic perspective of sleep, according to Bahammam, is derived from theological principles, with the Holy Quran describing sleep as a sign from God, and that within sleep, you are growing in his grace. This apparently encouraged a generation of medieval Islamic scholars towards empirical investigation of the phenomenon.
These intellectuals had commonality not only in their topic of research, but as the research identified, displayed a level of sophistication that confounds contemporary practitioners, establishing “foundational principles that influenced medical practice for centuries.” Abu Bakr Muhammad ibn Zakariya al Razi (865-925), or Rhazes, as he was known more widely, pioneered sleep while at the Baghdad Bimaristan, a pioneering place for the sick, a forerunner of today’s teaching hospitals, where many of the foundations of patient care were established. Rhazes holds prominence across all of medicine due to his ‘Kitab al Hawi fi al Tibb,’ revered as a comprehensive medical compendium, with a significant focus on sleep disturbances. His clinical observations on sleep paralysis and insomnia are still required reading in many doctoral courses.
Ibn al Jazzar (910-988), Head of the Kairouan Medical School, authored the Kitab al Nawm wa al Sahar, the Book of Sleep and Sleeplessness, in which he provided early clinical descriptions of hypersomnia and other sleep-related disorders, through clearly documented observations. These focused on the daytime sleepiness of torpor, narcolepsy, hypersomnia, and cataplexy and their possible links to epilepsy. Bahammam writes: “al Jazzar’s writings reveal an astute clinical awareness of sleep disorders and sudden motor disturbances, demonstrating the sophistication of Islamic treatment of complex neurological conditions.”
Abul Faraj ibn Yakub ibn Ishaq al Quff al Karaki (1233-1286), known as Ibn al Quff, was the leading medieval physician and surgeon of his time. Born in Jordan, he was a 13(th) century Arab physician-surgeon. Al Quff made important contributions to the art of healing, particularly the benefits of sleep in surgical recovery. He authored books and commentaries in medicine, particularly surgery, with the primary surgical textbook being his ‘Kitab al Umda fi al Giraha,’ the Basics in the Art of Surgery.
Ibn Sina (980-1037) was the Royal Court physician in Bukhara and Vizier, known as the “Prince of Physicians,” and the most prominent of sleep researchers, developing the pneumatic theory of sleep finding that sleep was a vital and active process necessary in maintaining energy, documenting the earliest references to what are known today as sleep apnea, stages of sleep, and rapid eye movements. His ‘Al Qanun fi al Tibb,’ his ‘Canon of Medicine,’ carries an aura of prescience and discovery, applauded worldwide.
Ala al Din Abu al Hasan Ali Ibn Abi al Hazm al Qarshi al Dimashqi (1213-1288), or Ibn al Nafis, practiced in Damascus and advanced understanding of sleep physiology by demonstrating that internal brain faculties remain active during sleep while external senses are suspended. Ironically, this was researched alongside his pulmonary circulation research, on which he was a prolific author, writing the ‘Sharh Mujaz al Qanun’, the ‘Sharh Tashrih al Qanun’, and the encyclopedic 80-volume ‘Al Shamil fi al Tibb,’ that are as specific today as they were then.
An average person will sleep more than 25 years, or 9,500 days, an immense 227,000 hours sleeping, and a further 50,000 hours of dozing, according to Gemma Curtis’s studies (2026). So... Ahmed, do we sleep too much?