Jet Lag

Jet lag, also known as time zone disorder or circadian dysrhythmia, refers to the set of symptoms that affect sleep and bowel function when traveling long distances across multiple time zones. It is a temporary disorder caused by the imbalance between a person’s internal clock and the new time zone established at the destination.

Symptoms

The symptoms and duration of jet lag vary depending on the person’s ability to adapt and the number of time zones crossed. The most common symptoms are:

• Insomnia
• Frequent awakenings during the night
• Lack of deep sleep
• Fatigue and general tiredness
• Sleepiness during the day
• Headache
• Constipation, vomiting, or diarrhea
• Difficulty concentrating
• Memory problems
• Irritability, anxiety
• Loss of appetite

Causes

As mentioned, jet lag is a disruption of circadian rhythms, which regulate the sleep-wake cycle based on periods of light and darkness. These rhythms form the so-called internal biological clock and are synchronized with the nighttime and daytime periods of the individual’s home time zone. Therefore, when crossing several time zones, the biological clock is out of sync by several hours with the destination’s time zone, and the body requires several days to adjust to this shift.

Risk Factors

The factors that increase the likelihood of experiencing jet lag are as follows:

• Number of time zones crossed: symptoms typically appear when more than three time zones are crossed, and they are more intense the more time zones crossed.
• Direction of travel: symptoms are stronger when traveling east, as the day is shortened and the body’s circadian rhythm must be shortened, making adaptation more difficult.
• Frequent long-distance flights.
• Age: older individuals have more difficulty adapting.

Complications

Excessive daytime sleepiness, combined with the loss of concentration and reflexes it causes, increases the risk of accidents, particularly work-related or traffic accidents.

Prevention

Several measures can be taken before traveling to prevent jet lag:

• Try to adapt to the new time zone: in the days leading up to the trip, go to bed and wake up later or earlier than usual, as appropriate.
• Get extra sleep the day before to avoid fatigue and recover sooner.
• Sleep during the flight if arriving in the morning, and stay awake if arriving at night.
• Stay hydrated during the trip.
• Once at the destination, adjust to the local time zone by following local meal and sleep schedules immediately.
• Exposure to light: try to stay outdoors during daylight hours to help the circadian rhythm realign.

Which doctor treats jet lag?

Jet lag is studied and treated in the sleep unit and aviation medicine department.