Flying long-haul with Type 1: pumps through security, time zones and the clock on your basal
Long-haul flights and crossing time zones with a pump: how do I handle basal and the missing/extra hours?
Your pump and sensor stay on your body through airport security: tell staff before you go through and ask for a hand search or the walk-through archway, not the full-body scanner. All your insulin and spares travel in your hand luggage, never the hold, where they can freeze and be ruined. The part to plan properly is time zones. Crossing them makes your day shorter or longer, and that changes when your background insulin needs to run, so your basal plan for the trip is worked out with your team before you fly, not improvised at 35,000 feet. Travel days move glucose both ways, so keep checking and keep fast sugar within reach.
- Keep your pump and CGM out of the full-body scanner unless your device maker says otherwise, and ask for a hand search instead; a travel letter and a medical device card make it quick.
- All insulin, pens, sensors and pump kit go in hand luggage, and it is worth carrying two to three times what you think you need, split across bags.
- Basal is your background insulin: on a pump the device clock drives when it runs, so crossing time zones and changing that clock changes your background timing.
- Flying east shortens the day and west lengthens it, which is why the plan is individual and set with your team, never a formula off a page.
- Travel days push glucose both ways: stress and sitting can raise it, missed meals and miles of terminal walking can drop it, and disrupted sleep keeps it unpredictable for days.
Security and packing, quickly
At the scanner, say it plainly: you have Type 1 diabetes, you are wearing an insulin pump and a glucose sensor, and they cannot go through the body scanner. Staff will usually offer a hand search or the walk-through archway metal detector, both of which are fine for pump and sensor with most manufacturers. What you are avoiding is the full-body scanner booth you stand inside, and the X-ray belt, because several device makers say those have not been tested on their kit. You do not have to take anything off to be searched, and a travel letter from your team plus the medical device card make the conversation short.
Packing has one hard rule: insulin stays in the cabin with you. The hold can drop below freezing, and frozen insulin is ruined even after it thaws. Carry two to three times the supplies you expect to use, insulin, pump consumables, sensors, spare pens and needles, plus a finger-prick meter and strips even if you normally rely on your sensor, and split it across two bags so one lost bag does not leave you with nothing. A cool wallet keeps insulin from cooking in a hot cabin or destination.
The clock on your basal
This is the bit that genuinely needs planning. Basal is the background insulin that runs all day and night, separate from your mealtime doses. On a pump, the pump’s own clock decides when each part of your basal runs, so changing the clock to a new time zone shifts your whole background pattern with it. On injections, your long-acting insulin is tied to the clock too, so a big time change moves when the next dose is due.
The principle is simple even though the plan is personal. Flying east, you lose hours, so your day is shorter and there is a risk of too much background insulin squeezed into fewer hours. Flying west, you gain hours, so your day is longer and there is a risk of a gap in cover. Which way you change the clock, and when, and anything to do with long-acting timing, is exactly the sort of dose-shaped decision that is worked out with your diabetes team before the trip. There is no safe one-size number for it, which is why this article points you at that conversation rather than giving you a rule.
Cabin pressure, meals and the days after
Two smaller things are worth knowing in flight. Cabin pressure changes on take-off and landing can nudge how much insulin a pump delivers, because tiny air bubbles in the reservoir expand and contract, so some makers give specific flying guidance such as removing air beforehand. It is worth checking your device’s advice rather than assuming. And meals arrive at odd hours while you sit still for a long stretch, then you walk miles through a terminal at the other end, so glucose can drift up from sitting and stress or down from walking and missed meals.
Afterwards, jet lag and broken sleep keep things unpredictable for a few days, and a low can turn up at an unfamiliar hour as your body clock resets. So keep checking through the whole disrupted period: roughly every couple of hours on a long flight, on landing, and across the first days at your destination while meals and sleep are still off-pattern. Keep fast-acting sugar where you can reach it without opening the overhead locker, and keep your backup pens accessible in case the pump has a problem far from home.
What changes the plan
No two trips need the same plan. The direction and how many zones you cross set the whole shape of the time change, and whether you are on a pump or injections changes how you handle it. A long flight means more hours sitting still, more odd-hour meals and more chance to drift. Sleep disruption and any alcohol on board both push toward lows at unfamiliar times, and your exact pump or sensor has its own airport and flying guidance. Because of all that, the personalised part goes to your team rather than a generic rule.
How a long-haul day goes
Examples, not instructions or doses.
You reach the scanner wearing a pump on your waistband and a sensor on your arm, tell the officer before stepping forward, and they route you through the archway with a quick hand pat on the pump. A couple of minutes, no drama.
You fly east overnight and lose several hours, so your day is shorter than usual. Because that squeezes your background insulin into fewer hours, you had already agreed with your team how to handle the clock before you left, rather than deciding it half asleep over the ocean.
Flying west you gain hours and the day stretches out, leaving a stretch where background cover could fall short. Having planned the clock change in advance meant you were not improvising an insulin decision in the air.
After landing your pump behaved a little differently for a while. Cabin pressure had shifted delivery slightly, which your device guidance had warned about, so you checked with a finger-prick rather than assuming the number was exact.
Worth paying attention to
Questions that make an appointment useful
When it's urgent
The emergency to plan for is losing your insulin supply, because a pump holds only rapid insulin with no long-acting backup in your body. If delivery stops (a failed pump, a lost bag) and you become high with ketones (the chemicals made when the body runs short of insulin), especially with vomiting, stomach pain, fast breathing, drowsiness or fruity-smelling breath, that can head toward DKA (diabetic ketoacidosis, a dangerous emergency). Check ketones if you can, use your backup pens, and call 999 or get to A&E, or the local emergency number abroad; do not let testing delay the call. For a lost or damaged supply that is not yet an emergency, a pharmacist or NHS 111 at home, or your travel insurance emergency line and a local pharmacy abroad, can help you get an emergency supply.