Adults should sleep for 7 or more hours a night on a regular basis, according to a joint consensus statement from the American Academy of Sleep Medicine and the Sleep Research Society. According to the evidence-based guidelines:
• Less than 7 hours of sleep per night is associated with adverse health outcomes:
o weight gain
o obesity
o diabetes
o hypertension
o heart disease
o stroke
o depression
o increased risk of death
o impaired immune function
o increased pain
o impaired performance
o increased errors
o greater risk of accidents.
• Sleeping more than 9 hours a night on a regular basis:
o may be appropriate for young adults, individuals recovering from sleep debt, and individuals with illnesses
o may or may not be associated with increased health risk.
Citation: Watson NF, Badr MS, Belenky G, et al. Recommended Amount of sleep for a healthy adult: a joint consensus statement of the American Academy of Sleep Medicine and Sleep Research Society. Sleep. 2015. pii: sp-00231-15.