1 Ouch – that hurts!

1.1 Why does it hurt?

The relief or avoidance of pain must be one of the major driving forces behind medical research. In this unit we start the discussion about relief of pain.

When we experience the sensation of pain it is likely that something is happening that the brain needs to know about, so it can direct us to whatever damage-limiting action is needed. We hurt because we have genes that constructed a body able to feel pain.

Without such a mechanism it is likely that life would be much shorter, with less opportunity to pass on our genetic code. It seems, therefore, that being able to feel pain is a state of affairs favourable to the continuing success of the species. This is unlikely to be foremost in the thoughts of someone who has just broken their leg or poured boiling water over their foot, but the fact remains that feeling pain is part of the defences that enable us to stay alive (Figure 1).

Figure 1: Pain in action. Feeling pain enables us to stay alive and pass on our genes