Types of Chronic Pain
Chronic pain (sometimes called intractable pain) is pain that lasts more than 6 months. Sometimes, there isn't a known cause of the pain; other times, there as an original injury, but the pain lingers after the injury heals. This is chronic pain, which can be divided into 2 broad categories:
- neuropathic pain: If your nerves themselves are damaged, that's neuropathic pain. You may have heard the term peripheral neuropathy; that's nerve damage to the peripheral nervous system.
- nociceptive pain: You have receptors in your nervous system called nociceptors. They are activated when there's an injury—and not until then. You can have an injury that activates your nociceptors, but then they can never turn off. They can malfunction and continue to send pain messages even after the injury heals; that's nociceptive pain.
Nociceptive pain is further divided into categories:
- visceral pain
- somatic pain
Visceral pain originates in the major internal organs. Viscera means organs that are inside a cavity, such as the abdominal or chest cavity.
Only some organs cause this deep, deep pain because not all of our organs have the same kinds of nerves going to them. Organs that have nociceptors—sensory nerves that transmit pain signals to the brain after an injury—can cause that deep, visceral pain if they're damaged.
The pain is often described as being achy, and because it comes from deep in the body, it can be difficult to pinpoint the location.
It's also difficult to pinpoint the location because visceral pain can also have a referred pain component: you can feel pain in other parts of your body.
For example, there can be something wrong with an organ in your abdomen, but the pain can travel to your back along nerve pathways. Therefore, you feel pain in your back, but it's really caused by an internal organ.
Somatic pain is often related to joint injury or arthritic conditions. Soma- is a Greek word root meaning "body." Somatic pain, then, is pain that comes from injuries to the outer body—as opposed to injuries to (or pain originating in) the inner organs. Skin, ligaments, tendons, muscles, joints, and bones can all cause somatic pain.
For example, you can develop bone pain as a result of cancer. Bone pain is often described as very intense dull or achy pain (unless it's a broken bone, in which case, that's acute, sharp pain).
Muscle pain is also a somatic pain, and it can develop as part of certain chronic conditions, including fibromyalgia.
The type of chronic pain determines the treatments, so it's important to understand the different categories of chronic pain.