Sleep at Altitude

Why is sleep disrupted at altitude?

Most people don’t sleep well at altitude. Hypoxia (Low oxygen) directly affects the sleep center of the brain. This results in frequent awakenings, light non restful sleep and less total sleep time. Many people, even full-time mountain residents have trouble sleeping despite acclimatization. Periodic breathing is the periodic cessation of breathing for 10-20 seconds during sleep at high altitude. This wakes a person many times throughout the night. This pattern happens automatically and is due to the low oxygen levels at altitude.

What is periodic breathing?

Periodic breathing is the alternation of periods of deep breathing and shallow breathing or cessation of breathing (apnea). Typically, three to five deep breaths will be followed by a few very shallow breaths or even a complete pause in breathing. This may end with a gasp that disrupts sleep. Periodic breathing is common at high altitude and gets worse with increasing altitude. Oxygen saturations drop during the apneic phases, causing gasping and awakening.

What causes periodic breathing?

Breathing faster at high altitude is one of the first responses your body has to altitude. It is the body’s attempt to get more oxygen. Every inhalation brings in oxygen – which is good. But every exhalation expels CO2. More exhalations lead to a significant reduction in carbon dioxide levels in the blood. CO2 is a stimulant to breath. When your body senses low CO2 levels it “thinks” that it no longer needs to breathe and stops breathing for a short while until it again senses low oxygen levels in the blood and resumes breathing with a gasp– often disrupting sleep.

Are oxygen bars effective to prevent altitude sickness or help you sleep better at altitude?

The short doses of oxygen at an oxygen bar may be enough for short term relief from altitude symptoms, but does not interrupt the exposure to hypoxia long enough to prevent mountain sickness from quickly returning. While oxygen will help you to sleep better in the mountains, it must be available during sleep.

Is an oxygen concentrator effective to help you sleep better at altitude?

Good sleep at altitude requires a few things: quiet, being comfortable, and sufficient oxygen. An oxygen concentrator provides oxygen, but is noisy, and it delivers the oxygen through a plastic tube called a cannula which most people find uncomfortable.

Is altitude sickness the same thing as altitude related insomnia?

Although acute mountain sickness and insomnia caused by high altitude are caused by the low oxygen levels at altitude, they are actually separate problems. Insomnia in the mountains can persist long after acclimatization even in full time mountain residents.