How Chronic Pain is Detected in the Nervous System


February 5, 2021

Chronic pain, also referred to as persistent pain, occurs when an ongoing tissue gets damaged. In some cases, there is no physical cause of pain and it can persist long after healing. Mostly the pain itself is a disorder rather than being a symptom of a particular disease.

Chronic pain can persist for months or years after an initial injury, and it can be a massive challenge trying to treat it. It is often characterized by sleeplessness, anxiety and depression. However, how does the nervous system detect chronic pain?

Nerves Identify Pain Sensations

The human body has different sensory nerve fibers that respond to various stimuli and produce different chemical responses that determine sensations’ interpretation. Some nerves react to light touch while others respond to deep pressure. However, if you are experiencing chronic pain, nociceptors are the pain receptors that get activated.

The nociceptors fire off a response whenever tissues get damaged. They send an impulse through the nerve into the spinal cord and eventually to the brain. It is something that takes place within a fraction of a second.

Role of the Spinal Cord

The spinal cord has an area called the dorsal horn. It is responsible for transmitting signals from one neuron to another across junctions known as synapses through chemical messengers (neurotransmitters). The spinal cord then passes the signals to the brain.

Interpretation of Pain in the Brain

The pain reflex takes place in the dorsal horn, but the pain signal continues to the brain. The pain is more than a simple stimulus or response. When it is chronic, it means you have a damaged tissue that is not healing as it is supposed to. Such pain upon reaching the brain goes to the thalamus and is then directed to other areas of the brain for interpretation.

The cortex figure determines where the pain is from and compares it with other familiar types of pain. It is part of the reason why you remember you have experienced the exact pain before. Likewise, some signals are also sent to the limbic system, the emotional center of the brain.

Understanding Pain Response

It may seem simple, but detecting pain is a complicated process. It is not a one-way or two-way system. It is more than the cause and effect. A lot goes on in the nervous system that affects how the pain will be interpreted. Mood, experiences and expectations can change the interpretation of pain. It is one of the reasons why there is a strong link between depression and chronic pain.

The problem with chronic pain is that the pain receptors fire continuously. It mostly happens with conditions that are continually causing damage, such as arthritis. In other cases, there could be the absence of tissue damage, but the nociceptors continue to fire. You will not have a physical cause of pain, yet you continue to experience chronic pain. It is the reason why chronic pain is quite a challenge to pin down.

If you are experiencing chronic pain in North Carolina, contact SEPSC to get the help you need and understand your situation better.