Every year World Health Day is celebrated on 7th April which is the day World Health Organization was born or came into existence. The World Health Day is based on a theme selected by World Health Organization and the theme of 2010 World Health Day is “Urbanization: a challenge for public health” and the World Health Day 2010 campaign is “1000 cities, 1000 lives”.

Why the theme?

The World Health Organization select a theme based on the importance of the particular subject and this year’s theme was selected to give importance to the public health problems of the cities across the globe. At present context the subject of healthy cities is very important as more than 50% of world population live in cities. In the year 2007 itself more than half of the world population started living in the cities, which is only growing and it is estimated that by 2030 more than 60% of the world population will reside in cities. Here lies the importance of urban health and so the World Health Day theme. At present more than 3 billion people live in cities.

Jet lag is a fairly common problem among people who undertake international travel, especially transmeridean travel. Jet lag is not seen if the journey does not involve transmeridean travel, even if journey is of several hours duration, e.g. traveling from London to Cape Town, a 7 hours journey.

What is jet lag?

The medical term of jet lag is “desynchronosis”. Jet lag is a condition due to alteration of normal cicardian rhythm of sleep by transmeridian air travel and there is disturbance in sleep, tiredness etc. Jet lag occurs due to transmeridian (east-west or west-east) air travel. More than 75 million people undertake transmeridian air travel annually and many of them experience jet lag.