One DALY can be thought of as one lost year of "healthy" life.
The sum of these DALYs across the population, or the burden of disease, can be thought of as a measurement of the gap between current health status and an ideal health situation where the entire population lives to an advanced age, free of disease and disability.
DALYs for a disease or health condition are calculated as the sum of the Years of Life Lost (YLL) due to premature mortality in the population and the Years Lost due to Disability (YLD) for people living with the health condition or its consequences.
A measure of the disease burden of a population which combines the loss of life from premature death, with the loss of healthy life from disability.
This burden-of-disease (of 100 different disease or health problems world-wide) variable is measured in units of disability-adjusted life-years.
The key elements are: the potential years of life lost as a result of death at a given age; the relative value of a year of healthy life lived at different ages; the discount rate used to indicate a time preference for human life and health; and disability weights to convert life lived with disability to a common measure with premature death.