Jet Lag and Its Short-Term Effects on Your Health

Traveling to new destinations is exciting, but the exhaustion, grogginess, and disorientation that follow long-haul flights can be frustrating. Jet lag is an all-too-common experience for frequent travelers, caused by a disruption to the body’s internal clock, also known as the circadian rhythm.

While jet lag is temporary, its effects can be significant—especially for individuals with sleep disorders like sleep apnea. This blog will explore the science behind jet lag, its short-term effects, and how it impacts people with existing sleep issues, backed by research from leading medical sources.

Understanding Jet Lag

Jet lag occurs when you rapidly cross multiple time zones, throwing your body’s natural 24-hour sleep-wake cycle out of sync with local time. The circadian rhythm is controlled by the brain’s suprachiasmatic nucleus (SCN), which responds to light exposure to regulate sleep, metabolism, and other bodily functions. When you travel across time zones, the SCN struggles to adjust quickly, leading to mismatched sleep signals.

A study led by Ambesh in 2018 found that the severity of jet lag depends on the number of time zones crossed and whether you travel eastward or westward. Eastward travel generally causes more intense jet lag because the body has a harder time advancing its internal clock. The disruption can last anywhere from a couple of days to over a week, depending on how quickly you adapt to the new schedule.

Short-Term Effects of Jet Lag

The immediate effects of jet lag go beyond simple tiredness. Some of the most common symptoms include the following.

1. Insomnia and Disrupted Sleep

One of the hallmark symptoms of jet lag is difficulty falling or staying asleep at night. Travelers who cross three or more time zones experience significantly reduced sleep efficiency and longer sleep onset latency. This means that even if you manage to sleep, the rest might not be as restorative as usual.

2. Daytime Fatigue and Drowsiness

Because your body is still functioning on your original time zone’s clock, you may experience excessive sleepiness during the day. Individuals who frequently experience jet lag report higher levels of exhaustion and impaired alertness compared to those with more stable schedules.

3. Cognitive Impairment

Your brain function can take a hit when your sleep schedule is out of sync. Research from the Journal of Neuroscience found that individuals suffering from jet lag performed worse on working memory tests compared to well-rested participants. This can be particularly concerning for business travelers or athletes who need to perform at high cognitive levels immediately after arrival.

4. Mood Disturbances

A disrupted circadian rhythm doesn’t just affect sleep; it can also impact emotional well-being. Research published by the McClung Lab indicates that disruptions in circadian rhythms can trigger or worsen symptoms of psychiatric and other disorders. These findings were supported by a 2023 study involving mice, where chronic jet lag caused decreased motivation and increased anxiousness and depressive moods. This explains why many travelers feel unusually irritable, anxious, or down after long flights.

5. Gastrointestinal Issues

Digestion is closely tied to the body’s internal clock, and disrupting circadian rhythms can lead to bloating, nausea, or changes in bowel habits. A study led by Qing Li in 2021 found that chronic jet lag disrupts gut microbiota, reducing microbial diversity. It also affects metabolism, lowering tryptophan levels (which impacts serotonin and melatonin production) and altering bile acid composition, which can affect digestion. These changes suggest that jet lag may contribute to gut imbalances and metabolic health issues over time.

How Jet Lag Affects People with Sleep Disorders

Jet lag is challenging for everyone, but for individuals with existing sleep disorders, it can be even more disruptive.

Jet Lag and Sleep Apnea

Sleep apnea is a disorder characterized by repeated interruptions in breathing during sleep. For those with obstructive sleep apnea (OSA), jet lag can worsen symptoms by fragmenting sleep further and altering breathing patterns. A study published in 2021 examined pilots experiencing jet lag after long-haul flights and found that 70.9% developed moderate-to-severe obstructive sleep apnea despite having no prior diagnosis, showing high apnea, respiratory disturbance, and oxygen desaturation levels. Factors like higher BMI and longer flight hours increased the risk, suggesting that daytime sleep after night flights may impact pilot health, fatigue, and flight safety.

Jet Lag and Other Circadian Rhythm Disorders

For individuals with delayed sleep phase disorder (DSPD) or advanced sleep phase disorder (ASPD), jet lag can further disrupt their already irregular sleep schedules. In fact, jet lag is recognized as one cause of circadian rhythm disorders.

Strategies to Minimize Jet Lag

While jet lag is inevitable for many travelers, several strategies can help mitigate its effects:

1. Gradually Adjust Sleep Before Traveling

Start shifting your sleep schedule by an hour or two in the days leading up to your trip. This helps ease the transition and minimizes circadian misalignment.

2. Get Plenty of Natural Light

Exposure to natural sunlight can help reset your internal clock faster. Morning light exposure helps if you’re traveling eastward, while evening light exposure is beneficial for westward travel.

3. Maintain Proper Sleep Hygiene

Stick to a consistent bedtime routine, even in a new time zone. Avoid screens before bed, keep your sleep environment cool and dark, and avoid caffeine or alcohol before sleeping.

4. Use Melatonin Supplements

Melatonin can help regulate sleep cycles, but should be used strategically. Taking melatonin at the right time can help reset circadian rhythms more quickly.

5. Consult a Sleep Specialist

If you suffer from sleep apnea, insomnia, or another sleep disorder, working with a doctor before travel can help you develop a tailored approach to managing jet lag.

Conquering Jet Lag and Sleep Apnea

Jet lag is more than just an inconvenience—it has measurable effects on cognitive function, mood, and physical health.

For individuals with sleep disorders, the impact can be even more severe. By understanding the science behind jet lag and implementing effective strategies, travelers can minimize its effects and enjoy their journey with better energy, focus, and overall well-being.

If you experience frequent jet lag and struggle with sleep disturbances, consulting a sleep specialist may be the best way to ensure a restful trip. Talk to the sleep experts at nightly.health before your next flight—or take our free online sleep quiz to assess the quality of your rest.

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