It’s nighttime and you’re exhausted. But the hotel bed feels wrong. The mini fridge won’t stop making that low, irritating hum. The power outlet lights feel brighter than the sun. Outside, random car honks and noises make sleep feel like a distant possibility.

Many of us struggle to sleep in new environments, even when we’re physically tired. But why? The short answer: a mix of biology and psychology.

Broken routines and missing sleep cues

Your brain is wired for predictability, especially at night, during our most vulnerable behaviour: sleep.

A combination of internal and external cues work together to create the right conditions for rest.

Internally, your body signals that it’s time to sleep by decreasing core body temperature and increasing the sleep-promoting hormone melatonin. This makes you less alert.

Externally, your environment needs to support these signals, not compete with it. At home, your typical pre-sleep wind-down habits and familiar surroundings tell your body it is safe to sleep.

But sleeping somewhere new often disrupts these sights, sounds and sensations your body relies on.

There may be different light levels (for example, from hotel room clocks or street lights), unfamiliar noises (such as elevators, traffic and neighbours) and different bedding (for instance, a firmer........

© The Conversation