Referred vs Radicular Pain: What is the difference and why does it matter?

Pain is pain. Right? It turns out that it may not be that simple.

Neck pain and low back pain are two common conditions that chiropractors spend the majority of their time treating on a daily basis. Most of the time, the pain that is associated with these two conditions is called “mechanical” in nature, meaning that the pain is coming from the muscles and the joints associated with the injured area. However, there are two different kinds of pain that are different than the pain associated with the injury itself: referred pain and radicular pain.

Referred pain is pain that is felt in a location other than where the initial injury occurred. For example, many people experience gluteal or hip pain when they injure their low back, or shoulder and arm pain when they injure their neck. Just because there is pain in an area, doesn’t mean that the tissues in that area have undergone a tissue injury. Referred pain is a consequence of nerve networks that associate many different areas of the body and your brains inability to accurately map where the exact source of pain is coming from. While the exact mechanism is still not fully understood, the most recent theories stem around the fact that nerves from multiple areas in your body converge at the same level of your spinal cord, and your brain struggles to decide which of these areas the pain is coming from. Referred pain tends to be dull and aching, and is a “diffuse” pain that is not well localized to a specific point but is felt more in a region. Interestingly, it is not just muscles and joints that can refer pain, but organs can refer pain too. This is the reason why someone undergoing a heart attack can feel pain down their left arm, or a kidney stone is felt as pain in the low back. The two following images are referred pain maps for two things that are seen every day in chiropractic clinics: cervicogenic headaches and low back pain. The “x” marks which muscle is painful, and the red dots indicate the areas of referred pain.

Referral pattern for the quadratus lumborum muscle.

Referral pattern for the suboccipital muscles leading to cervicogenic headaches.

Radicular pain is also referring to pain that is felt at a location that is away from the initial point of injury, but in this case it is a nerve root that is irritated and the pain is felt along the course of that nerve in the body. The best example of radicular pain is a disc herniation leading to sciatica. When the initial disc injury occurs, there is going to be pain in the lower back at the level of the injury. However, due to the nature of disc herniations and the associated inflammatory response, the adjacent nerve roots that make up the sciatic nerve can also become irritated. This irritation of the nerve roots (or in some cases the nerve itself) will lead to pain that travels along the course of the nerve. In the case of the lumbar nerve roots, that is commonly down the back of the leg and into the foot. While this does sound similar to referred pain, radicular pain IS felt in a tissue (in this case a nerve) that has undergone some type of tissue damage or irritation. Radicular pain is generally felt as a lightning or burning type pain that travels along the entire length of the nerve that is irritated.

Typical course of lumbar radiculopathy leading to radicular pain along the sciatic nerve.

What does this mean for me?

The good news is, while both of these types of pain can feel widespread and in multiple areas of the body, they are generally the result of a single injury. In the case of referred pain, it is usually a single muscle or joint that becomes irritated, and once treated both the local pain of the injury and the referred pain will both clear. What seems like neck pain and headaches may actually be the same problem, and treatment of the neck pain will lead to the resolution of both problems.

In the case of radiculopthy things can get a little bit more complication. Because there is a nerve involved, there can be muscle weakness and sensory changes (numbness) that accompany the radicular pain. This generally means that radicular pain is more bothersome than referred pain, as there are more symptoms involved. However, like in the case of referred pain, once the source of the problem is treated, all of the symptoms should begin to resolve concurrently.

For a detailed examination of your condition and the best way to treat your type of pain, visit your local health professional for a proper diagnosis and treatment plan and get back to living pain free!