The largest-ever study of ancient DNA reveals the shifting ancestry of Central and South Asian populations over time.

Why do some people with TB develop active disease soon after infection, while others appear to remain healthy?

VIDEO: Neurobiologist Dragana Rogulja explores why we need to sleep and how lack of sleep can harm us.

Incorrect discharge of patients back to their homes could put them at risk of inadequate care. A new study looks at Medicare payment reform.