Painkillers 'are the cause' of millions of headaches
19 September 2012 Last updated at 07:55 BST
Up to a million people in the UK have "completely preventable" severe headaches caused by taking too many painkillers, doctors have said.
The warning came as part of the National Institute for Health and Clinical Excellence's (NICE) first guidelines for treating headaches.
Dr Brian Hope says anyone taking painkillers for more than 15 days during a month were likely to suffer from analgesia-induced headaches.