CPAP travel: flying, power abroad, water, camping and altitude

Traveling with a CPAP is easier than it looks once you know the rules. You can carry it through security, take it on board without using up your carry-on allowance, and in many cases use it in flight. The rest comes down to planning for power, water and where you'll sleep. This guide covers flights, trips abroad, camping and mountain stays, so you can keep your treatment going wherever you are.

Should you take your CPAP when you travel?

Yes, take your CPAP when you travel. NHLBI says to use your PAP machine for all sleep, including naps, and to bring your breathing device with you when you travel. Cleveland Clinic says the same: for treatment to work, you have to use CPAP every time you sleep, including while traveling and during naps.

That holds for short trips too. Cleveland Clinic acknowledges that CPAP can be cumbersome to travel with, but says there are ways around the obstacles and that it's important to stick with treatment. A little planning keeps one awkward bag from costing you a week of good sleep. If you're still getting used to the mask at home, our guide to getting used to CPAP can help before you go.

How do you get a CPAP through airport security?

You can take a CPAP through airport security in either your carry-on or checked bag. TSA says CPAP, BiPAP and APAP machines, along with masks and tubing, can stay in their carrying case for X-ray screening. At standard screening you may be asked to take the case out of your carry-on. With TSA PreCheck, it can stay in your carry-on.

TSA also says devices with lithium metal or lithium ion batteries should be carried in carry-on bags. In practice, most people carry their CPAP on board so it can't be lost or damaged in the hold. Put the mask and tubing in a clean bag inside the case, since they may be handled at screening.

If you bring water or other liquids for the machine, tell the officer. TSA allows larger amounts of medically necessary liquids in reasonable quantities, but you must declare them at the checkpoint for inspection.

Does a CPAP count toward your carry-on limit?

No, under Department of Transportation rules, airlines must not count assistive devices toward a passenger's carry-on limit. The rule, 14 CFR 382.121, covers medical devices brought into the cabin, as long as they can be stowed in the overhead bin, under a seat or in a priority storage area, and meet safety rules.

It's still sensible to mention the CPAP when you book, especially on smaller planes or with foreign airlines, and to keep it in a clearly marked case.

Can you use a CPAP on a plane?

Often, yes. Under 14 CFR 382.133, US airlines flying planes designed for more than 19 passengers must let you use a CPAP in the cabin if it displays a manufacturer's label showing it meets FAA requirements. Foreign airlines on flights to, from or within the US have a similar duty, under their own government's rules where those exist.

Airlines can set conditions, and they must explain them when you ask during booking. The rule lets them:

• Ask you to contact them 48 hours before departure to learn the expected maximum flight time, so you know how many batteries you need
• Require enough fully charged batteries to run the device for at least 150% of the expected maximum flight time
• Ask you to check in up to an hour before their usual check-in deadline
• Set a maximum size and weight for devices used in the cabin

Spare batteries must be packed and protected from short circuits. Don't count on a seat power outlet. Plan to run the machine on battery, and call the airline well before you fly. If you only need CPAP on a long overnight flight, ask your doctor whether you need it in the air at all, or whether careful planning around sleep is enough.

What are the battery rules for flying with a CPAP?

The FAA says spare lithium ion and lithium metal batteries, including power banks, must travel in carry-on baggage only. If a carry-on is checked at the gate, spare batteries must be taken out and kept in the cabin. Battery terminals must be protected from short circuits, for example in their original packaging or with tape over the contacts.

There are size limits. The FAA limits rechargeable lithium ion batteries to 100 watt hours each. With airline approval, you can carry up to two spare larger batteries of 101 to 160 watt hours. It adds that many airlines have stricter limits on numbers and sizes, so check with yours. The watt-hour rating is usually printed on the battery.

How do you power a CPAP abroad?

Check the input rating printed on your CPAP's power supply before you go. If the voltage range it lists covers your destination's mains supply, you'll usually need only a plug adapter for the local sockets. If it doesn't, ask your equipment supplier what to use rather than guessing with a converter.

A few other habits help. Pack a short extension lead, since hotel outlets aren't always near the bed. Bring spare filters and a spare mask cushion on longer trips. And keep the user manual or a photo of the model and serial number on your phone in case you need help while away.

Do you need distilled water when traveling?

Distilled water is the usual recommendation for a CPAP humidifier, at home or away. Sleep Foundation explains that tap water can contain minerals that cause buildup or scaling in the humidifier and can support bacterial growth, and that boiling kills germs but leaves the minerals behind. Bottled drinking water often has minerals too, so check that the label says distilled.

For flights, Sleep Foundation suggests buying distilled water at your destination rather than packing it. If you can't find any, it says you can use CPAP without the humidifier for a while, or use a heat and moisture exchanger, which adds humidity without water. It also advises emptying and drying the water tank before you pack, to prevent leaks and bacterial growth. If your mouth or nose dries out without humidification, our guide to dry mouth with CPAP has more ideas.

What about travel CPAPs and camping?

Smaller travel CPAP machines exist, and some can run on batteries, which helps for flights, camping and places without reliable power. Many are lighter because they drop the built-in humidifier, which is where a heat and moisture exchanger can fill the gap. Whether a travel machine suits you depends on your prescription and settings, so talk to your doctor or equipment supplier before buying one, and check whether your insurer covers a second device.

Camping takes the most planning. Work out how many hours your machine runs on one battery charge at your settings, using the manual or your supplier. Running a humidifier from a battery usually uses more power, so many campers turn it off. Keep batteries off cold ground and out of direct sun, and bring a way to recharge if you're out for more than a night or two.

What changes when you sleep at altitude?

Sleep apnea can get worse at altitude, even with CPAP. In a 2012 randomized trial in JAMA, 51 people with sleep apnea who lived below 800 meters spent nights at Swiss mountain resorts at 1,630 and 2,590 meters. With autoCPAP and a placebo, the median apnea-hypopnea index was 10.7 an hour at the lower resort and 19.3 at the higher one.

Adding acetazolamide, a prescription medicine, helped. With acetazolamide plus autoCPAP, the median index fell to 5.8 and 6.8 an hour, and oxygen levels at night were higher. At 2,590 meters, the median share of the night spent with oxygen below 90% dropped from 57% to 13%.

If you're heading to the mountains, talk to your doctor beforehand about whether your settings or medicine need to change. Our guide to sleeping at altitude explains why breathing changes up high and which altitude sickness symptoms need urgent help.

A quick CPAP travel checklist

For the rest of your sleep kit, see our travel sleep checklist. If you snore through your CPAP on the road, snoring with CPAP covers common fixes. This article is general information, not medical advice. Rules change, so check with your airline and TSA before you fly.

Read next

• Sleeping at altitude: why breathing changes and what helps
• How to get used to CPAP
• What to pack for better sleep when you travel

* This content is for informational and educational purposes only and is not medical advice. It is not intended to diagnose, treat, cure or prevent any disease or health condition. Talk to a qualified healthcare provider about your health.