chronic pain. it's not something _ chronic pain. it's not something that - chronic pain. it's not something that is i chronic pain. it's not - something that is commonly talked about. people get on with it and it gets to a point that people become incredibly disabled and distressed and i don't think we are equipped over as a society or as a healthcare over as a society or as a healthca re system to over as a society or as a healthcare system to deal with that pain, you probally know the prevalence of pain is anything between 20% at 50% in the uk and we know that it's massive. the uk and we know that it's massive-— massive. well as an issue affecting _ massive. well as an issue affecting millions - massive. well as an issue affecting millions of- massive. well as an issue i affecting millions of people, chris says the mechanism of how persistent pain works is not well understood. for example, if we have _ well understood. for example, if we have pain _ well understood. for example, if we have pain in _ well understood. for example, if we have pain in our- well understood. for example, if we have pain in our need, i if we have pain in our need, the senses in our knee may be sending normal information to our nervous system. that data reaches the spinal cord and the spinal cord will learn do what it wants to do on that signal and it may boost the signal and it depends largely than on the decision—making process to turn that into a threat signal or a normal signal. and also an for