Waking at 3 A.M.? How Sleep Patterns Often Shift With Age

Melatonin levels naturally decline with age, causing lighter sleep and earlier wake times.

Another influence is the natural shift in the circadian rhythm, the body’s internal clock. Many older adults start feeling tired earlier in the evening. If bedtime shifts to 8:30 or 9:00 p.m., waking at 3:00 or 4:00 a.m. may simply be the completion of a full night’s sleep. Lifestyle changes such as retirement, spending more time indoors, or getting less natural daylight can also affect this internal rhythm. Physical discomfort, medications, caffeine later in the day, and long naps may contribute as well.