BBC health correspondent James Gallagher investigates how our noisy world is damaging our health. He finds out why noise increases our risk of health problems, like heart attacks, sleep problems and anxiety, and can even affect how long we live. James spends two days in Barcelona – one of the noisiest cities in Europe – to meet the people whose health is being ruined by noise and the scientists and doctors trying to solve the problem. He also visits London to be experimented on in a lab to find out how noise changes the body, and hears from Dhaka, capital of Bangladesh, one of the loudest places on the planet.