What is jet-lag?

jet-lag blueball Fatigue
Being worn out and tired for days after arriving, generally accompanied by a lack of concentration and motivation, especially for any activity that requires effort or skill, such as driving, reading or discussing a business deal. But even simple daily activities can become harder, and one's capacity to truly enjoy a tourist holiday is significantly reduced.

Disorientation, fuzziness
Having to return to check three times to see if a hotel room was left locked or unlocked is a typical symptom reported by flight crews experiencing jet-lag. Again, not good if you're on a business trip.

Becoming irrational or unreasonable
"Losing it" is another symptom reported by aircrew, which explains why long-haul flights get very tedious near the end, and why going through customs and immigration and getting to the hotel often seems like a real drama.

Broken sleep after arrival
Crossing time zones can cause you to wake during the night and then want to fall asleep during the day at your new location. Your inbuilt circadian rhythms have been disturbed, and it can take days for the body to readjust. NASA estimates you need one day for every time zone crossed to regain normal rhythm and energy levels. So a 5-hour time difference means you may require five days to get back to normal! Can you afford that?

In addition to the above symptoms of jet-lag, the syndrome is made worse by some common physical problems caused by being confined in an airliner for hours:

Dehydration
This can cause headaches, dry skin and nasal irritation, and make you more susceptible to any colds, coughs, sore throats and flu that are floating round in the aircraft.

Discomfort of legs and feet
Limbs swelling while flying can be extremely uncomfortable, and in some cases may prevent travellers wearing their normal shoes for up to 24 hours after arrival.

A report from the World Health Organisation directly links jet-lag with problems of diarrhoea caused by microbiological contamination of water or food, which it says affects about 50% of long-haul travellers. "Factors such as travel fatigue, jet-lag, a change in diet, a different climate and a low level of immunity may aggravate the problem by reducing a traveller's resistance and making them more susceptible to this type of infection or poisoning," the report says.