The Long Night: Sleeping Well at Altitude

Ask travellers what surprised them most about altitude and many will not mention the walking — they will mention the nights. Sleep at altitude is famously light, broken and odd, and the good news is that this is normal, expected, and improves within a few days. It is rarely a sign that anything is wrong.

The reason is straightforward: at altitude your body wrestles, even in sleep, with the basic problem of getting enough oxygen. Understand what is happening in those long first nights and you can stop fighting them — and do the handful of things that genuinely make rest come easier.

Why altitude breaks your sleep

During the day, low oxygen makes you breathe faster; this is helpful, but it also blows off carbon dioxide, and carbon dioxide is part of how the brain knows when to breathe at all. At night the result is periodic breathing — deep breaths, then a pause, sometimes long enough to feel like the breath has stopped, then a sudden gasp. It can wake you, or your travelling companion, with a jolt.

This pattern, sometimes called Cheyne-Stokes breathing of altitude, is extremely common above roughly 2,500 metres and is not in itself dangerous. It tends to be worst in the first nights and to settle as acclimatisation proceeds. Knowing it is coming takes much of its alarm away.

What a normal bad night high actually feels like

Expect to wake several times, to dream vividly, to feel you have barely slept, and perhaps to surface around three in the morning convinced you cannot get enough air. Expect, too, a dull headache on some mornings and a flat appetite at breakfast. In a place like Cusco at 3,400 metres, this is the ordinary texture of the first two or three nights.

It is worth separating this normal disturbance from a warning sign. A poor, fragmented sleep is expected. A relentless headache that does not respond to rest and simple painkillers, breathlessness while simply lying still, or a persistent cough are different — those are reasons to speak to your guide, not to endure quietly.

The habits that help you rest

Sleep lower than you climbed: spend the day high if the itinerary allows, but bed down a few hundred metres below your day’s peak — the climber’s principle of climb high, sleep low is, above all, a sleep strategy. Avoid alcohol and heavy sedatives in the first nights, because both blunt the breathing drive you actually need. Keep the room cool but yourself warm, and prop your head up slightly.

Hydration matters more than it seems: the dry mountain air pulls water from you invisibly, and a mildly dehydrated body sleeps worse. Drink through the day, though taper in the last hour or two so the cold walk to the bathroom does not become the thing that wakes you. A light, carbohydrate-leaning evening meal sits easier than a rich one.

Medication, oxygen and the question of sleeping pills

Acetazolamide, the common altitude medication, happens to be particularly good at smoothing periodic breathing and is sometimes taken specifically to improve sleep on the first high nights — but whether it suits you is a conversation for your own doctor before departure. Conventional sleeping tablets are best treated with caution at altitude, as the older sedative types can suppress breathing; never start one high without medical advice.

Many Andean hotels help in gentler ways. Several Cusco properties, including historic houses on Andes to Antarctica, offer optional oxygen enrichment in the rooms, which can noticeably ease a first night. A small bottle of supplementary oxygen by the bed, which our guides can arrange, does the same. None of this replaces acclimatisation — but on night one, a little help is no weakness.

Why the first nights are placed where they are

A well-built itinerary treats sleep as a design problem. It puts your first high nights at the lowest workable altitude, never stacks consecutive jumps in sleeping height, and gives you an arrival day with nothing demanding the morning after a guaranteed-broken night.

On Andes to Antarctica this is why the first nights are often spent down in the Sacred Valley rather than up in Cusco, and why no demanding dawn start ever falls on the first morning at altitude. By the time the journey asks something of you, several settled nights are behind you — and a rested traveller meets the mountains very differently from a sleepless one.