Overcoming jet lag.

Jet lag is a symptom complex resulting from travel across time zones, which can incapacitate travellers for several days. It is a result of the abrupt changes forced on travellers' sense of time, place and wellbeing, and on their internal cycles. It is manifested in its early phase by exhaustion out of proportion to the length of the flight, disorientation to time, and disruption in sense of wellbeing, memory and performance. In the later phase, profound exhaustion, constipation or diarrhea, anorexia, insomnia, headache, and limited night and peripheral vision may be experienced. Light, food, methylated xanthines (coffee, tea, etc.), physical and mental activity, alcohol and smoking affect bodily rhythms. Awareness and manipulation of these 'cues' before, during and after a flight can significantly reduce jet lag.