How much sleep do adults actually need each night?

Most adults need 7 to 9 hours of sleep per night, according to the National Sleep Foundation and the CDC. This range applies to the majority of people aged 18 to 64, while adults 65 and older may do well with 7 to 8 hours. Individual needs vary somewhat due to genetics, health, and lifestyle, but the idea that some people genuinely thrive on 5 or 6 hours is largely a myth. Chronic short sleep is associated with increased risk of obesity, heart disease, diabetes, and cognitive decline. Consistently needing an alarm to wake up or feeling drowsy during the day are signs you're probably not getting enough.