This important worldwide activity was created by the WHL and first held on May 14, 2005, with the theme: Know Your Numbers! WHD was a resounding success with 24 countries participating, and since then World Hypertension Day has been an ever expanding yearly event. It's purpose is to communicate to the lay public the importance of hypertension and its serious medical complications, and to provide information on prevention, detection and treatment. To do this requires cooperation of health care professionals, media, volunteer organizations and government in each country.

In 2023, the theme is Measure Your Blood Pressure Accurately, Control It, Live Longer, focusing on combatting low awareness rates worldwide, especially in low to middle income areas, and accurate blood pressure measurement methods.