The circadian rhythm is the body’s internal clock that regulates the sleep–wake cycle. As we age, this rhythm may shift earlier, meaning older adults often feel sleepy in the early evening and wake up very early in the morning.

Respecting this rhythm can help improve sleep quality:

• Get natural sunlight exposure in the morning to help reset the internal clock.

• Avoid artificial lights in the evening, especially blue light.

• Stay physically and socially active during the day.

Disruptions to the circadian rhythm can lead to sleep disorders such as insomnia or excessive daytime sleepiness.