A Strange Sleep Phenomenon At 10,000+ ft

On a recent trekking trip in Nepal, a friend gave me some pretty weird news: at night, I would alternate between hyperventilating and holding my breath in my sleep. I guess when you ‘sleep for a living’ (i.e. work for Zeo), it’s a little harder to get away from talking about stuff related to work.

Keeping a Positive Altitude

After a couple of days in Kathmandu (the capital of Nepal), I started hiking in the Mt. Everest region – from Lukla (elevation 9,380 ft) to Gokyo Ri (elevation 17,600 feet). I hadn’t done too much hiking at that altitude, so I wasn’t sure what I was in for. The first few days were great, with spectacular views, friendly people, and no problems with altitude.

Things got tougher four nights and roughly 12,000 feet into the trip – I had a headache, and only slept from about 3am to 6am. The next morning, my friend told me about my strange nighttime breathing (and breath-holding)…

Don’t Hold Your Breath

After a few nights like this (with a bit more total sleep), a met a doctor from New Zealand in a small town called Machermo (13,500 feet). We wound up in a long conversation about what was happening to me at night – which apparently is called periodic breathing. Here I was, 7,500 miles from home, having a conversation about sleep. It turns out periodic breathing is actually fairly common at altitudes above 10,000 feet.

Here’s a quick summary of what I learned about periodic breathing:

1. High altitude = not much oxygen. And my body tried to compensate by breathing faster (hyperventilating).
2. Hypverventilating = low CO2 levels. This decreased level of CO2 indicated to my body that I didn’t need to breathe, causing my breathing to slow dramatically and even stop.
3. Stop breathing = not much oxygen. As oxygen levels in my blood began to drop (because I wasn’t breathing), the whole process would start all over again.

Interestingly, my periodic breathing experience seemed pretty similar to sleep apnea. Just like apnea, periodic breathing caused me to stop breathing for extended periods of time at night. It certainly affected my sleep – leaving me groggy and slow the next day.

Feet Back on the Ground

Unfortunately, I didn’t bring Zeo with me on my trip – extra weight on a hike like this, not to mention the lack of electricity in remote places, meant it stayed behind. In the end, though, it would have been nice to have my Zeo. It would have been fascinating to look at my sleep at altitude with periodic breathing, and contrast it to my typical night’s sleep.

All in all, an amazing trip, and a great opportunity to learn a little more about sleep.

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Andrew “Moose” Schwartz is an Associate Brand Manager at Zeo. When not trekking around the world, he’s making sure that Zeo offers the best products and services possible to our customers.