What Is Jet Lag?


Jet lag Signs Symptoms And Treatment

Jet lag is the name given to a range of symptoms experienced whilst trying to adapt to a new light-dark schedule. After your international flight enters a new time zone your internal body clocks find it difficult to adjust.


Your natural 24 hour body clocks influence sleeping and waking patterns (circadian rhythms) which have adapted to your normal time zone; these are influenced by light and social interaction. When you change time zones you will still wake up and feel tired at your preset times but these times will be inaccurate in the new time zone.


  • You are in Australia and usually wake up at 6am and feel tired at 11pm
  • You fly to New York leaving 9am Thursday the 6th of May
  • The flight is around 20 hours so around 11pm Australia time you will feel tired and may take a nap on the plane.
  • You then arrive in New York at 7pm on Wednesday the 5th of May
  • You should be getting ready for bed at 11pm which is in four hours New York time but your body clock is still set to Australia time so it thinks it is 9am and has no intentions of preparing for bed – your body clock is ready to start the day.

 As you can see it is confusing just reading the example. Your body clock needs to digest all of this new information and then adapt to it. This can take anything from a couple of days to a week.


Jet lag symptoms are generally reported as being worse for easterly flights compared with westerly flights crossing the same number of time zones.

If you cross 1-2 time zones most people will not experience jet lag. If you cross 3-6 time zones most people experience moderate jet lag and if you cross 7 – 12 different time zones most people will experience moderate to severe jet lag symptoms which may including:


Most Common Symptoms

  • Sleep Disturbance – hard to stay awake during the day, hard to sleep at night, poor sleep quality
  • Memory and concentration problems


Other Symptoms

  • indigestion
  • diarrhea
  • constipation
  • loss of appetite
  • Nausea
  • lightheadedness
  • feeling disorientated
  • confusion
  • clumsiness
  • irritability
  • anxiety 
  • lethargy (lack of energy)
  • headaches
  • sweating
  • muscle soreness
  • irregular periods in women who travel frequently
  • generally feeling unwell


Treating jet lag

There is no magic pill and no conclusive studies have been done on jet lag cures, but a few common sense approaches may help alleviate the discomfort.


When you arrive at your destination:

  • Establish a new routine as fast as possible – eat and sleep at your normal times. If you went to bed at 11pm Australian time, start going to bed at 11pm in the new time zone
  • Don’t sleep when you arrive because you are tired. Wait until the normal time (as above)
  • Your natural body clocks are influenced by light and social interaction so go outside and socialize, this may help speed things up

Consider melatonin.

Melatonin is a  naturally secreted hormone which helps regulate our circadian rhythms so that we sleep at night.

There is no conclusive evidence that medications containing melatonin have any effect on jet lag and you may experience side effects.

  • Headaches
  • Dizziness
  • Day time sleepiness

May Interact With:

  • Anticoagulants (blood thinning medications)
  • Immunosuppressants (medications that suppress the immune system)
  • Diabetes medications
  • Birth control pills