Understanding the process of Hazm (Digestion) in Unani medicine: A physiological correlation with modern GI function

Unani medicine describes Hazm (digestion) as a coordinated process involving four stages—gastric, hepatic, vascular, and organ-level digestion—each contributing to the transformation of ingested food into nourishment for the body. Modern gastrointestinal physiology defines digestion as a mechanical and chemical breakdown involving the mouth, stomach, intestines, enzymes [14], microbiota [9], hormones, and neural regulation. This review explores the parallels between these systems, emphasizing how classical Unani concepts mirror modern understanding in function, sequence, and systemic integration. A comparative analysis reveals conceptual harmony in the roles of digestive heat (Hararat-e-Ghariziyah [3]), Quwā-e-Hazimah (digestive faculties), and nutrient absorption through organs and vessels.