Neurologist V. S. Ramachandran, author of Phantoms in the Brain, says, “There is no direct hotline from pain receptors to ‘pain centers’ in the brain. [Instead,] there is much interaction between different brain centers, like those concerned with vision and touch.”
What this means is the exact opposite of saying that pain is “all in your head.” It means that pain is a summary of all the data that come into your brain from your whole body, your environment, your relationships, feelings, and beliefs. If the summary says, “Things are not well,” you will likely feel pain. Chronic pain is a whole body–mind experience. It always has a physical component, and it always has an emotional component, and there may be other factors as well.
What causes chronic pain?
Chronic pain can reflect injury that hasn’t completely healed. More often, it is caused by nerves that have become oversensitive or by a brain that is misreading the signals it receives. If acute pain goes on too long, nerves and brain can tire of the constant signals and just decide the injury is permanent. That’s why it’s important to treat acute pain seriously. For example, if you injure your foot or your back and don’t treat it promptly — with adequate rest, other first-aid measures, and seeing a doctor if the pain is severe or persists — mild pain can become severe, and acute pain can become chronic.
A good way to understand the many causes of chronic pain is by considering phantom limb pain. When people lose an arm or leg in an accident or surgery, about half of them will still feel that the limb is there. About half of those people develop serious pain in the phantom limb. Obviously, this isn’t due to physical injury going on in the moment. It’s a misunderstanding by the brain of the signals it is getting and not getting. The brain figures the signals add up to something seriously wrong, so it sends out an urgent pain message.
The same thing applies to the chronic back and leg pain so many people have. There may be a few pain signals coming up from tired muscles or joints toward the brain. Those signals go through nerve centers called “pain gates.” Those “gates” are where the signals are mixed with other sense data, feelings, and body states such as tension. In people with chronic pain, the gates amplify the signals over and over until the pain is severe. They do this because the brain thinks the person needs to be warned away from a real threat, such as taking a hand out of the fire so it doesn’t burn.
Anything that makes nerves more sensitive can increase pain. Feelings of stress, fear, helplessness, or anger can increase pain sensitivity. Trauma — such as a physical injury or psychological or sexual abuse — often leads to chronic pain later on. In a study of people with traumatic injuries conducted by researchers at the University of Washington in Seattle, nearly 63% had severe pain one year later. It may be that trauma causes nerves to become oversensitive as a way of trying to prevent further injury. This may be why military veterans have the highest rates of chronic pain.
Chronic pain creates several vicious cycles. For one, people tend to tense their muscles in response to pain, which often makes the pain worse. Pain also leads people to stop moving, which leads to increasing stiffness and more pain. Pain can interfere with sleep, and restless nights can increase pain. Pain also can contribute to depression and painful emotions such as anger, grief, fear, and frustration, which in turn contribute to pain.
Since chronic pain has so many contributing causes — physical, mental, and emotional — there are many ways to break into the pain cycle, reduce pain levels, and gain comfort. There may not be a cure for chronic pain, but a person can gain some control over his pain. Feeling more in control, even a little bit, can help people relax, try new things, and gain even more control. In this way, even severe chronic pain can be managed, and the person with pain can gain better health in the process.