Can this painful involuntary muscle contraction be prevented?Subscribe: http://bit.ly/SubscribeToEarthLab

All the best Earth Science videos http://bit.ly/EarthLabOriginals
Best of BBC Earth videos http://bit.ly/TheBestOfBBCEarthVideos
The Doctors Are In The House http://bit.ly/TheDoctorsAreInTheHouse
Best Of Earth Unplugged Videos http://bit.ly/BestOfEarthUnpluggedVideos

Trust Me I'm A Doctor: Series 3
Michael Mosley and his team of doctors return to tackle more questions about our health, offering uncomplicated, trustworthy advice on important and topical medical issues.

Welcome to BBC Earth Science! Here we answer all your curious questions about science in the world around you (and further afield too). If there’s a question you have that we haven’t yet answered let us know in the comments on any of our videos and it could be answered by one of our Earth Science experts.