Pain: What is it?

Pain is a private event that occurs within the nervous system, usually in response to injury. The perception of pain, which occurs at the cortical level of the brain is unpleasant, usually eliciting a withdrawal response. There is a profound emotional component to pain that is both an immediate response to injury and an amplifier of the response. From an evolutionary perspective, pain protects from danger and identifies injuries that we may not be able to see. There are peripheral receptors that fire in response to injury sending signals to long neurons in the spinal cord. These neurons end in the thalamus. From there secondary neurons radiate to the cortex, bringing the signal of injury to our consciousness.

This multi level anatomical mechanism is important in the treatment of pain because the signal that is generated in the periphery can be suppressed or down regulated along its path. 

As an example, if you talk to a child, or distract them in some way before a painful procedure, the emotional  response to the perceived injury will be attenuated and the intensity of the pain can be suppressed or eliminated. If you scratch a child’s leg while someone is putting in an IV, the intensity of the pain can be reduced. The combination of oral versed and a topical anesthetic with a funny face or a cute toy will reduce much of the pain that accompanies modern hospital care for children.

The anatomy and the physiology of the human body that produces, transmits, and perceives the signal allows us to treat pain in a sophisticated manner. When you see a child having trouble, think about all the levels at which the astute clinician can attack the problem.

Rae Brown, M.D., FAAP