This document discusses disability-adjusted life years (DALYs), which are used to quantify the burden of disease. It provides background on DALYs, explaining that they measure the number of healthy years of life lost due to ill-health, disability or early death. It describes the components used to calculate DALYs, including years of life lost (YLL) and years lived with disability (YLD). It also gives examples of how DALYs are estimated for specific diseases and regions, such as estimates for worldwide disease burden and DALYs in Bangladesh for 1990.