Chronic pain is a debilitating condition that affects 14 million people in England alone.
But scientists think the have come a step closer to understanding it - by studying those who do not feel it at all.
Cambridge University researchers have identified a faulty gene that seems to switch pain off in some people and it is hoped the discovery could lead to new treatments for those who live with pain every day.
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http://www.bbc.co.uk/news/health-33105759