What Is Pain?

Pain can sometimes be a bit of a mystery. The brain evaluates a whole series of sensory inputs from the tissues and other systems and then decides whether to make a particular body part feel pain or not. While many people think of pain as a negative, it is quite often more protective than harmful. When the brain senses that the body is in danger of becoming damaged in some way, it uses pain as a method to get the body out of the way of the harm.
This motivational factor of pain is one of its most important functions. If you are touching a hot stove, the resulting painful burning sensation gets you to move your hand further away from the source of harmful heat. And if you have sprained your ankle, the resulting swelling and inflammation is your body’s method of getting increased nutrients and blood to the area in order to promote healing, while the pain of walking on that sprained ankle is the brain’s way of telling you not to overuse the injured area until it has healed some.
Pain, then, does not reflect what is actually going on in the tissues, per se. What the brain does is, when it perceives that the tissues may be in danger, it creates a pain message to motivate us to take steps to protect ourselves from those conditions which may cause damage. A feeling of pain indicates perceived danger; it does not always indicate damaged tissues. This is an important distinction to understand when dealing with pain, especially chronic painful conditions.
Just as important is the brain’s ability to turn off a pain message. Once you move your hand away from the hot stove, within a few minutes the pain may be all gone. If you have sustained a serious burn, it may take hours or days for the pain to subside, even though it may take weeks for the actual burned tissues to heal all the way. This goes back to the protective quality of pain — once the brain perceives that the danger has decreased, the pain message is no longer necessary to motivate protective behaviors.
However, pain is not the only thing going on with the tissues and brain when danger is sensed. As mentioned above, if you sprain your ankle, there is swelling and inflammation, which promotes faster healing and isolation of the damaged tissues. But these processes may not be enough to promote healing, if you keep walking or running on the injured ankle. The brain also sends the pain message through the nervous system to the foot to make sure that you tread very carefully on it for a few weeks until the healing process has progressed enough so that there is not imminent danger to the tissues anymore. The whole body works together to heal and prevent further injury.
The pain system is really a very useful set of processes that the body and brain have acquired to help protect us from danger and further injury. For the most part, they work extremely well together to keep us from seriously harming ourselves. Think of how difficult life would be if there was no pain from touching a hot stove, but tissue damage would result anyway. We would need to use our even more conscious senses to constantly monitor whether we are in danger of damaging ourselves or not. While no one thinks they want pain, it is often the most effective method to get us to change our behaviors so that we do not injure or kill ourselves inadvertently.