This document provides an overview of international health and the history of international health organizations. It discusses how diseases know no borders and early international efforts focused on quarantine practices to control disease spread. The first international health conferences in the 1850s aimed to standardize quarantine measures but had little success. Over time, organizations like the Pan American Health Bureau in 1902 and the Office International d'Hygiene Publique in 1907 were formed to promote cooperation on international health issues. Major milestones included the founding of the World Health Organization in 1948 to coordinate global health initiatives and address both communicable and non-communicable diseases.