Sex

For decades, medicine treated the human body as a relatively universal model, with little consideration for sex differences beyond the reproductive system. Recent research has revolutionized this approach, demonstrating that biological sex - determined by sex chromosomes (XX in females and XY in males) and associated hormonal differences - influences almost every aspect of human physiology and health outcomes. This fundamental biological variable affects everything from cellular metabolism to drug responses, making it a crucial consideration in modern medical practice and research.