Before death, patients tend to follow 1 of 3 general trajectories of functional decline: A limited period of steadily progressive functional decline (eg, typical of progressive cancer) A prolonged indefinite period of severe dysfunction that may not be steadily progressive (eg, typical of severe dementia, disabling stroke, and severe frailty) Function that decreases irregularly, caused by periodic and sometimes unpredictable acute exacerbations of the underlying disorder (eg, typical of heart failure or COPD [chronic obstructive pulmonary disease]) With the first trajectory (eg, in progressive cancer), the course of disease and time of death tend to be more predictable than with the other trajectories.