Uncovering the effects of too little, too much and just the right amount of sleep; how to get a better night's sleep.

James Harrison has saved more than two million babies by donating his precious life-saving blood nearly every week for last 60 years.

The world's largest floating hospital is built inside a converted oil tanker; this U.S. Naval hospital ship has traveled the world to save lives; CNN's Dr. Sanjay Gupta is on board the USNS Comfort as it docks in Kingston, Jamaica.