Tens of thousands will leave Great Britain this year for medical treatment.

The National Health Service is a taxpayer-funded system open to every British citizen. It has been such a resounding success since it was implemented in 1948 that Britons are now traveling in large numbers to get care elsewhere.

In a country with a population of 61 million, 70,000 will leave this year after 60,000 sought treatment abroad in 2006. By the end of the decade, this year's number will nearly triple, to 200,000.