When something hurts it’s hurting in the brain, not in the limb. That’s why you can have ‘phantom limb’ pain. It’s all about the nerve receptors transmitting the information to the brain. Sometimes the information is scrambled, mis-directed or just plain wrong.
Think of this – you might be in a restaurant worrying about a toothache when the waiter drops a whole tray of dishes which come crashing to the ground, and your attention is taken away from the hurt. The toothache disappears for the time your attention is somewhere else.
if you want a full explanation of why pain hurts please view the entertaining and informative video by Professor Lorimer Moseley below.