Older adults frequently wake earlier in the morning than they did when younger.

The longer version

With age, the internal clock often advances, so sleepiness arrives earlier in the evening and the night ends earlier. Sleep also becomes lighter and more fragmented, with more brief awakenings and less of the deepest slow-wave stage. Daytime naps become more common again, and total sleep across a day may not fall as much as night sleep does.

That advance reflects changes in the clock itself rather than any external demand, and it helps explain early evening drowsiness alongside pre-dawn waking. Reduced exposure to strong daytime light and lower activity levels may reinforce the pattern. Not every older adult follows it, and individual differences in the clock are large at any age.

Where this entry sits

This collection gathers curious details about sleeping and dreaming, from nightly brain stages and body clocks to naps, yawns and unusual animal habits. It also covers how bedtime customs have changed across centuries, without offering any advice. The full list sits on the Sleep and Dreams page, where every entry is listed in order.