Abstract: By the practical nature of the case, here is no theoretical argument but pragmatic reasoning for washing hands, with scientific evidence of hand-washing flushing out diseases into a sanitary condition globally. All facts found show some people surviving long without hand-washing, not denying healthful hand-washing, spreading health. Hand-washing remains a medium simplest most efficacious for global health. Thus this essay delivers an important message of global health by routine hand-washing, in four sections. 1) It describes what is hand washing (Section 2). 2) How to wash hands is concretely specified (Section 3). 3) Exceptions are responded to (Section 4). 4) How pivotal such an easy practice of hand washing is to global health is elucidated, to clinch the whole crucial issue at stake worldwide (Section 5).