Jet lag is a familiar companion for long-haul travelers.
Its symptoms range from mild fatigue to days of grogginess, headache, and brain fog.
Yet its intensity differs sharply from person to person, says Dr Bikky Chaurasia, Consultant, Internal Medicine, Kokilaben Dhirubhai Ambani Hospital, Mumbai.
Speaking to this publication, Dr Chaurasia noted that jet lag reflects a mismatch between the body’s internal clock and the local time at the destination.
“How quickly that clock re-aligns depends on age, baseline sleep health, and the direction you fly,” he said.
The result: some travelers bounce back overnight, while others need nearly a week.
Age: slower body clocks, slower adjustment
Older adults often feel it more
“Ageing reduces circadian flexibility,” Dr Chaurasia explained.
Melatonin secretion may become blunted and sleep becomes lighter with more awakenings.
That makes it harder for older adults to shift bedtimes by an hour or two per day after a long flight.
He added that coexisting conditions—hypertension, diabetes, or medications that affect alertness—can compound the drag.
Recovery may take longer, particularly after multi-time-zone, eastbound flights.
Planning extra buffer days can help older travelers pace their schedules.
Pre-existing sleep disorders: a stacked deck
Insomnia, sleep apnea, restless legs worsen symptoms
Travelers with insomnia carry sleep debt into the journey.
“Jet lag magnifies that deficit,” Dr Chaurasia said, pointing to delayed adjustment and daytime sleepiness.
Obstructive sleep apnea, if untreated, further fragments sleep and worsens morning fatigue after time-zone shifts.
Restless legs syndrome can flare with long periods of immobility.
Cabin conditions—dry air, cramped seating—may aggravate symptoms.
Clinicians advise treating the underlying disorder first to reduce jet-lag fallout.
Travel direction: east is tougher than west
Shortening the clock is harder than stretching it
Human circadian rhythm tends to run slightly longer than 24 hours.
“That bias favors westward travel,” Dr Chaurasia said, because you can fall asleep later and wake later.
Eastbound trips demand earlier bedtimes—effectively “shortening” the internal day—which is biologically harder.
Rule of thumb: expect roughly one day of adjustment per time zone when flying east.
Westbound recovery is often faster, though still influenced by individual factors.
Strategic light exposure and timing of sleep can reduce the gap.
Other modifiers: chronotype, time zones crossed, and timing cues
Morning larks vs night owls, plus flight logistics
Chronotype matters.
“Larks” who naturally wake early adapt more easily to eastward advances.
“Night owls” cope better with westward delays but struggle with early local mornings.
Severity also scales with the number of time zones crossed.
Red-eye departures, late-night arrivals, and multiple layovers add strain.
Well-timed daylight, meals, and activity at destination act as anchors for the body clock.
For a primer on circadian basics, see our internal guide: Understanding Your Chronotype.
Travel planning tips are here: Jet Lag Playbook for Long-Haul Flights.
Authoritative sleep-health resources are available from the NHS and CDC:
NHS – Jet lag advice and CDC – Healthy travel & sleep.
Dehydration, caffeine, alcohol: small choices, big effects
Cabin environment and stimulants can amplify jet lag
Airplane cabins are dry and pressurized, promoting dehydration.
Even mild fluid loss can worsen headache, fatigue, and perceived jet lag.
“Hydration before, during, and after flight is a simple win,” Dr Chaurasia said.
Caffeine and alcohol both disrupt sleep architecture.
Late-day caffeine delays melatonin onset; alcohol fragments the second half of sleep.
Limiting both near destination bedtime supports earlier realignment.
Practical ways to reduce symptoms
Shift before you fly, time your light, anchor your mornings
Dr Chaurasia recommends pre-flight shifting of bedtime and wake time by 30–60 minutes per day, especially for eastbound trips.
On arrival, seek morning daylight when you need to shift earlier, and avoid bright evening light that pushes the clock later.
Sunglasses in late afternoon and blue-light reduction after dusk can help.
Anchor the new time zone with consistent wake time, protein-rich breakfast, and daytime activity.
Short 20–30 minute naps can restore alertness, but avoid long afternoon sleeps that delay the night schedule.
Discuss melatonin or sleep aids with a clinician if you have a sleep disorder or take other medications.
When to seek medical advice
Persistent insomnia, severe daytime sleepiness, or mood changes after travel warrant evaluation.
Travelers with sleep apnea should use their CPAP consistently and review settings before trips.
Those with cardiovascular, psychiatric, or neurologic conditions should seek individualized plans.
“Jet lag is common, but it’s not trivial if it repeatedly affects safety, mood, or chronic disease control,” Dr Chaurasia cautioned.
An evidence-based plan—timed light, sleep scheduling, and, when appropriate, supplements—can make long-haul travel manageable.
Preparation remains the strongest antidote.
Bottom line
Jet lag doesn’t strike everyone equally.
Age, sleep health, and flight direction set the baseline, while habits and timing cues tip the balance.
With a few targeted strategies, most travelers can shorten recovery and protect performance on the road.
