We introduce Psychoeconomics of Healthcare Decisions, a novel interdisciplinary field that sheds light on the "why" behind our medical choices. This field explores the intricate web of psychological factors, economic considerations, and individual behaviors that influence healthcare decision-making. By examining the impact of cultural contexts and socio-economic environments, Psychoeconomics of Healthcare Decisions offers a deeper understanding of patient choices. This knowledge has the potential to revolutionize healthcare delivery by empowering patients, informing policy decisions, and ultimately promoting preventive care utilization and treatment adherence. This manuscript lays the groundwork for this nascent field, outlining its potential to improve public health outcomes.