This Shortwave episode examines the complexities of sex differences in medical research, tracing the history from the exclusion of women in trials to current binary categorization issues. Hosts Emily Kwong, Aru Nair, and Dr. Angela Zhang discuss how oversimplifying sex into two buckets can lead to misdiagnoses, such as in heart attacks, and problematic drug dosing like Ambien. Experts argue for more precise definitions and inclusive practices to move toward precision medicine while addressing societal biases in healthcare.