One of the most common types of radiating pain is the leg pain referred to as sciatica. The sciatic nerve is comprised of nerve fibers, which come from multiple levels of spinal nerves in the low back. The most common cause for sciatica is compression and/or inflammation of one or more of the spinal nerves in the back, although the sciatic nerve can be compromised directly. The condition is called radiculopathy and it can also occur in the upper extremity from irritation to the nerves in the neck or cervical spine.   

Combined Patterns of Pain

Spine conditions often lead to a combination of different patterns of pain because there is often more than one type of tissue involved. For example, a herniated intervertebral disc may displace an adjacent spinal ligament resulting in regional back pain. The same disc herniation may also be large enough to compress an adjacent spinal nerve resulting in radiating pain, which travels along the course of the nerve.

The muscles surrounding the involved area of the spine may spasm leading to more regional pain as well as an element of referred pain distant from the area of back involvement.

Complex Regional Pain Syndrome

Complex regional pain syndrome (CRPS) is a neuropathic pain syndrome characterized by a criteria list of signs and symptoms. It more commonly afflicts an extremity and does not usually occur as a primary spine problem, although spinal nerve compromise might contribute to its development in an extremity. This condition was priviously known as reflex sympathetic dystrophy syndrome (RSD).  CRPS is a generally uncommon, chronic pain condition. The disorder is characterized by severe spontaneous pain, disproportionate pain and hypersensitivity of the involved area, intense burning, joint stiffness, muscle spasms, swelling, skin discoloration, altered temperature and other trophic changes of the skin. It may also be associated with abnormal sweating. There may also be changes in skin color and texture. The skin can become, thin and shiny over the involved area.

The exact underlying cause is not clearly understood.  Women are more likely to develop CRPS than men. The condition most commonly in individuals between the ages of 40 and 60, but it can occur at any age. Treatment is usually most effective when initiated early.