This treemap visualizes global high blood pressure rates, showing each country as a rectangle whose area represents the estimated population with high blood pressure and whose color indicates the prevalence rate, using an RdYlGn sequential color scale where darker reds denote higher percentages. The visualization, built with React and d3.v7, uses `d3.treemap()` to compute the hierarchical layout, groups rectangles by world region with labeled headers, and displays country names and prevalence percentages inside each cell. Hover interactions reveal a formatted tooltip with the country, prevalence rate, and affected population. Data comes from the World Health Organization's NCD Risk Factor Collaboration 2019 dataset.