How golden age Arab-Islamic scholars revolutionized sleep physiology and dream analysis.

Résumé

Medieval Arab-Islamic scholars (7th-13th centuries CE) made pivotal but underacknowledged contributions to sleep science, blending empirical observation with theological insight. This review examines primary texts, especially al-Rāzī's and Ibn Sīnā's , alongside secondary literature to illuminate their advanced understanding of sleep physiology, disorders, and dreams. Al-Rāzī pioneered early clinical methodologies, using comparative groups to evaluate treatments for sleep disorders. He offered detailed observations of (sleep paralysis), distinguishing between gastric and brain-centered types, and addressed conditions such as insomnia and nocturnal enuresis. His sleep hygiene recommendations, emphasizing diet, routine, and emotional balance, align strikingly with modern best practices. Ibn Sīnā's pneumatic theory of the (psychic spirit) provided a mechanistic explanation for sleep-wake transitions and proposed three sleep stages based on pulse changes. He also provided an early and clinically relevant description of symptoms consistent with obstructive sleep apnea, recommending positional therapy. His analyses of sleep posture, digestion, and pharmacology demonstrate a systemic approach that is still relevant today. Ibn al-Nafīs expanded sleep theory by arguing that internal faculties like imagination remain active during sleep, prefiguring modern understandings of selective neural activation. Ibn al-Jazzār described hypersomnia () and epilepsy-related collapse, hinting at early notions of narcolepsy. Islamic dream theory, grounded in the Qur'an and Prophetic traditions, recognizes dreams as both physiological phenomena and spiritual messages. Medieval Arab civilization scholars developed and refined classification systems that distinguished divine visions from psychologically and physically induced dreams, an approach that bridged theology, philosophy, and proto-psychology. Together, these contributions demonstrate that medieval Islamic scholars laid key foundations for sleep medicine, challenging Eurocentric histories and affirming the enduring value of diverse intellectual traditions.