Sleep, perchance to dream—and to awaken restored, energetic, and prepared to meet the challenges of the day. The evolutionary gift of sleep lowers the risk of chronic disease, and supports brain health, immune function, and emotional regulation. Yet one in three adults say they don’t get enough sleep and as many as 70 million Americans suffer from insomnia, narcolepsy, sleep apnea, or another sleep disorder. Cultivating the right habits can improve the quantity and quality of your sleep and align your shut-eye with your body’s circadian rhythms.