How did Rudolf Virchow use microscopic cells to explain disease?

Rudolf Virchow revolutionized medicine by applying cell theory to pathology, shifting the understanding of disease away from the ancient "humoral" model—which attributed illness to imbalances in bodily fluids—and the later focus on organs or tissues in general.12

Instead, Virchow demonstrated that diseases originate primarily within individual cells. Influenced by the work of researchers like Robert Remak, who established that cells arise from preexisting cells, Virchow championed the principle that pathological processes are essentially cellular processes. He argued that in a diseased state, the fundamental unit of life—the cell—is altered.12

By systematically studying these microscopic changes, Virchow transformed scientific thought, establishing a framework where the diagnosis and understanding of disease are rooted in the physiological and pathological study of tissues at the cellular level. His work, most notably detailed in his 1858 lectures and subsequent book, Cellular Pathology, provided the foundation for modern medical diagnostics and our understanding of how human disease manifests within the body.21