Too little or too much sleep may damage your health, study warns

A new study in the journal Nature has found that too little or too much sleep can harm health. Researchers warn that both short and long sleep durations affect key organs, including the brain, heart, and immune system. The findings reinforce existing advice on maintaining balanced sleep habits. The American Academy of Sleep Medicine advises adults to sleep at least seven hours a night. New research now suggests a range of six to eight hours for optimal health. Sleeping fewer than six hours has been linked to irritability, mood swings, and poor concentration during the day.

A consistent sleep schedule helps regulate the body’s circadian rhythm and melatonin levels. Experts also recommend creating a sleep-friendly environment: dimming lights, using blackout curtains, blocking blue light, and keeping the bedroom cool. Avoiding alcohol before bed can further improve sleep quality.

Exercising in the morning or afternoon supports better rest, but late-night workouts may disrupt sleep. Meanwhile, oversleeping—more than eight hours—can reduce light exposure and activity, potentially speeding up the ageing of the body’s internal clock.

For children, sleep needs vary by age, ranging from eight to 16 hours. The study also noted that chronic sleep deprivation or excess can contribute to mild depression over time. The research highlights the risks of both insufficient and excessive sleep. Keeping a steady sleep routine and a healthy sleep environment can help protect organ function and overall well-being. Balanced sleep remains a key factor in long-term health.