2. Shifts in the internal clock (circadian rhythm)
Another common cause is a shift in the body’s internal timing system.
Many older adults feel sleepy earlier in the evening. If someone goes to bed at 9:00 p.m., their body may naturally complete its sleep cycle around 3:00 or 4:00 a.m.
This isn’t always insomnia — sometimes it’s simply a new rhythm.
The shift can become more noticeable when:
- A person retires
- Social interaction decreases
- Daily responsibilities lessen
- Evenings become quieter
- Without strong external cues, the body relies more heavily on its internal clock.
