Chronic Emergency: Why NCDs Matter examines the magnitude of the challenge posed by noncommunicable diseases (NCDs) in middle- and low-income countries, and makes the case for elevating the challenge as a priority item to address on the agenda of decision-makers. NCDs are on the rise in all middle- and low-income country regions. By 2030, NCDs are expected to account for three quarters of the disease burden in middle-income countries, up from two-thirds today and approaching the level of high-income countries. In low-income countries, the NCD share of the disease burden will increase even more quickly and will approach the levels currently found in middle-income countries. At the same time, many low-income countries will continue to contend with substantial communicable disease burdens, thus facing a ―double burden‖ of disease. Further, compared to their higher-income counterparts, many developing countries will face elevated NCD levels at earlier stages of economic development and with a much compressed timeline to address the challenge.