By Jonny Lupsha, Freelance News Writer

An arthritic woman in Scotland reports feeling virtually no pain after two separate surgeries, according to Scientific American. Her diagnosis suggests a new gene mutation with potential for treating acute and chronic pain. Usually, of course, a person’s body acutely perceives pain and needs medication to alleviate it.

Arthritis is usually quite painful, sending aches and discomfort through the joints. Undergoing hand surgery to treat severe arthritis is also painful. Doctors were shocked when a 66-year-old Scottish woman required no pain medication during her recovery from such surgery—doubly shocked when she reported no pain whatsoever from a separately diagnosed osteoarthritis condition in her hip, due to serious bone degeneration, and which required hip replacement surgery. Her lack of discomfort flies in the face of modern medicine’s understanding of the human body and pain management.

The Three Types of Pain Perception

The human body plays host to three different systems that send pain signals to the brain. “The first, and in many ways the most basic, is nociceptive pain,” said Dr. Peter M. Vishton, Associate Professor of Psychology at William and Mary. Nociceptive pain is activated by the body’s sense of touch perception—mainly, pressure and temperature. “Extreme cold, extreme heat, or extreme pressure will activate those heat, cold, and pressure receptors,” Dr. Vishton said. He explained that when nearly any neuron is destroyed or even damaged, its final task is to send off a strong signal to the brain that the body is being damaged, which we interpret as pain.

Next is inflammatory pain. As the name suggests, this is pain that stems from swelling in the body. When you stub your toe, the immediate pain is nociceptive pain; however, “the aches and pains that follow for days after are inflammatory pain,” Dr. Vishton said. “As your body works to repair damage to your muscles, skin, and other tissues, it sends a lot of extra blood and fluid to that area.” It does this because all the materials needed to repair the toe are carried in those fluids. Likewise, it serves as a reminder to your brain to avoid using that part of your body while it heals.

Finally, the third kind of pain is neuropathic pain, which comes from damage to the nervous system itself. Although many things can injure the neurons that make up the nervous system, the most common example is Carpal Tunnel Syndrome. Carpal Tunnel Syndrome can affect people who perform repetitive motions for activities such as sewing; using tools for a long period of time; or, of course, typing on a computer keyboard. But why? “If your wrists are bent at one particular upward angle for long periods of time, it can put stress on the many nerve fibers that run from the arms into the hands,” Dr. Vishton said. “Many of the muscles that move your fingers are not in the hands, but in your forearms. As they contract and relax, moving back and forth sometimes dozens of times per second, that pressure can slowly damage the nerves.”

Why We Need Pain

Congenital Analgesia, or a congenital insensitivity to pain, is a rare condition “from birth to death that inhibits the ability to perceive physical pain,” according to a website on rare diseases from the National Institute of Health. At first glance, this may seem like a dream come true. However, nothing could be further from the truth.

First, consider nociceptive pain. Nociceptive pain tells us when an external threat to the body is damaging us so we can respond and stay alive. Looking back at the Scientific American article, the woman in Scotland reportedly told doctors that in the past, she’d only realized her hand was burning when she smelled her own flesh cooking. Likewise, painful, bleeding cuts tell us to wash, disinfect, and bandage the wound immediately. A congenital analgesic patient may be cut on an object and never know it until an infection spreads, complicating the wound.

Second, inflammatory pain and neuropathic pain go hand in hand. In the examples given earlier, the pain experienced tells us to stop using a part of our body that’s being overworked. If we never sense these warnings from our bodies, we may overuse damaged muscles or nerves to the point of permanent failure. That may not seem like an issue with a stubbed toe—you’ve probably got nine others—but the severity becomes clear if we apply the same thought to irreversibly losing the function of muscles in our upper legs, forearms, or neck.

One day, doctors may successfully adapt the arthritic Scottish patient’s gene mutation to walk the line between the dangers of congenital analgesia and the relief of acute and chronic pain. Currently, regular aches and pains—unpleasant as they may be—keep us safe and remind us which parts of our body need rest, repair, and recovery.

Dr. Peter M. Vishton contributed to this article. Dr. Vishton is Associate Professor of Psychology at William & Mary. He earned his Ph.D. in Psychology and Cognitive Science from Cornell University. He has also taught at Northwestern University and served as the program director for developmental and learning sciences at the National Science Foundation.