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What Happens to Red Blood Cells When They Age?

With an average lifespan of about 120 days, human red blood cells (RBCs) undergo a series of progressive changes that signal their eventual removal from circulation. As red blood cells age, their membranes become more rigid, and their metabolic activity declines, marking them for clearance by specialized immune cells. This natural process, known as erythrocyte senescence, is a vital part of maintaining blood homeostasis.