Alternative names for jet lag What is jet lag? Jet lag is the
disruption to sleep or activity patterns and the ability to be
alert and function effectively. This is due to rapid travel
across time zones, which leads to the body’s internal timing
systems being out of alignment with the external time cues of
the final destination, particularly the light-dark (day-night)
cycle and local clock time. What causes jet lag? The primary
cause of jet lag is the abrupt change in local time cues (for
example sunrise, sunset, light and dark) after flight across
several time zones. The body’s internal circadian clock is
unable to adapt rapidly to such a swift change. It takes
approximately a day for each time zone crossed for the internal
clock to realign with local time. Thus, for a number of days,
depending on the number of time zones crossed, the clock is in
‘night mode’ during the day and ‘day mode’ during the night. Our
ability to sleep, stay alert, perform different tasks and digest
our food is best when the internal