Death by Rousui in Japan: Rethinking Death, Diagnosis, and Care in an Aging Society

In Japan, death from old age—rousui—is officially recognized on death certificates and is now the third leading cause of death. Rousui describes a gradual decline in physiological function leading to death without a specific underlying disease. As a family physician, my first diagnosis of rousui occurred two decades ago, for a woman in her 90s whose decline was slow, multidimensional, and free of reversible causes. While culturally accepted, rousui remains undefined in clinical terms, creating uncertainty in diagnosis and care. This ambiguity influences end-of-life decision making, sometimes leading to overmedicalization or undertreatment. As populations age globally, Japan’s experience offers valuable lessons on how to recognize, document, and care for those dying from aging itself—inviting a broader discussion on aligning medicine with the natural trajectory of life’s end.