"Why do people experience pain differently when they go through the same event?" asks Claire Jenkins from Cwmbran in Wales.

Professor of Pain Research, Irene Tracey, welcomes Adam in to the room she calls her 'Torture Chamber'. Burning, electrocuting, lasering and piercing are all on the menu, but which will hurt the most?

Hannah speaks to Steve Pete from Washington who has a rare genetic condition which means he doesn't feel pain. For chronic sufferers, this sounds like heaven, but a life without pain has brought untold suffering to him and his family, including the tragic story of his brother, Chris.

We look at how the body creates pain, why some people feel it more than others, and how this knowledge could help scientists treat pain more effectively in the future.

Presenters: Adam Rutherford, Hannah Fry