World Hypertension Day (WHD) Every year, 17 May is dedicated to World Hypertension Day (WHD). This is an initiative of the World Hypertension League (WHL), an affiliated section of the ISH. The WHD was first inaugurated in May 2005 and has become an annual event ever since. The purpose of the WHD is to promote public awareness of hypertension and to encourage citizens of all countries to prevent and control this silent killer, the modern epidemic.