Sleep problems, including random eye movement (REM), snoring, sleep apnea, sleep deprivation, insomnia, shift work sleep disorder, and narcolepsy, are common nowadays. Good sleep is vital for optimal health and can affect mood, hormone levels, and weight. For example, sleep is involved in healing and repair of your heart and blood vessels. Experts argue that sleep deficiency is linked to an increased risk of heart disease, kidney disease, and high blood pressure.