Jet Lag Disorder


Jet lag, or jet lag disorder, is a temporary condition that impacts sleep patterns for individuals who rapidly traverse multiple time zones. This condition arises because the body operates on its own internal clock, known as circadian rhythms, which dictate sleep and wakefulness cycles. When you travel swiftly across different time zones, your internal clock remains aligned to your original time zone instead of adjusting to the new one, leading to jet lag. The severity of jet lag often correlates with the number of time zones crossed, causing various symptoms including daytime fatigue, feelings of malaise, difficulty maintaining alertness, and gastrointestinal issues.

Although the symptoms of jet lag are temporary, they can significantly impact one’s enjoyment and performance during vacations or business trips. However, there are proactive measures that can be taken to mitigate or even prevent the onset of jet lag. By understanding the mechanisms of jet lag and its effects on the body, travelers can adopt strategies to align their internal clocks with their new environment, reducing the discomfort associated with this disorder and enhancing their overall travel experience.


Jet lag symptoms can manifest in various ways, and you might encounter one or multiple symptoms, such as:

  • Sleep difficulties, including trouble falling asleep or waking up early.
  • Impaired focus or reduced functionality compared to your usual level.
  • Stomach issues like constipation or diarrhea.
  • A general sense of unwellness.
  • Extreme tiredness at daytime.
  • Headaches
  • Irritability
  • Mood changes

Symptoms of jet lag usually appear within one to two days after crossing at least two time zones. The intensity and duration of these symptoms often escalate with longer travel distances, especially when traveling eastward. Typically, it takes approximately a day to recover for each time zone crossed.

While jet lag is temporary, frequent travelers experiencing recurrent jet lag may find consulting a sleep specialist helpful in managing their symptoms.


Jet lag, often encountered by travelers crossing two or more time zones, disrupts the body’s internal clock, known as circadian rhythms. These rhythms govern not only our sleep-wake cycle but also influence various bodily functions, including appetite and digestion. Adjusting to a new time zone typically requires a few days, during which one’s daily routines might feel out of alignment with the local schedule.

The influence of sunlight on circadian rhythms

The production of melatonin, a hormone pivotal for synchronizing our cellular functions, is significantly influenced by sunlight. The process begins in the eye, where light is detected and signals are sent to the brain’s hypothalamus. This triggers the pineal gland to adjust melatonin release according to the time of day—increasing it at night to promote sleep, and decreasing it during daylight to help us stay awake and alert. Leveraging natural light exposure at strategic times can aid in quicker adaptation to new time zones.

Additional contributors to jet lag

  • Air pressure and altitude: Research suggests that the altered cabin pressure and high altitudes experienced during flights may play a role in jet lag symptoms, even without crossing time zones.
  • Airplane cabin humidity and water intake: The typically low humidity levels found in airplane cabins can lead to dehydration if not countered with adequate water intake, potentially intensifying the effects of jet lag.

Risk factors

Factors that heighten the probability of experiencing jet lag include:

  • The number of time zones crossed: The greater the number of time zones you traverse, the more susceptible you are to feeling jet lag.
  • Flying east: It might be more challenging to cope with jet lag when flying east, leading to a “loss” of time, compared to flying west, which involves a “gain” in time.
  • Being a frequent flyer: Individuals frequently engaged in air travel, such as pilots, flight attendants, and business travelers, are more prone to experiencing jet lag.
  • Being an older adult: Older adults may require more time to recover from jet lag compared to younger individuals.