Disc pain, or discogenic pain, is leg pain or lower back pain that is experienced due to degenerative changes to the intervertebral discs of the spine. This type of pain is distinguished from a pinched nerve pain, or nerve root compression, because it is actually the disc itself that is painful in this case. Until recently, it was thought that most cases of back pain and sciatica were due to disc herniations in which the disc material ejected out of the tears in the discs impacted the nerves exiting the spine. When the expelled disc material presses into the spinal nerves, the resulting back pain symptoms include radiating pain (radiculopathy), numbness, sharp pain, muscle weakness, and burning. It was though that as long as the disc disease did not result in the nerves themselves being impacted, the patient would not experience any painful symptoms. It was thought that the discs themselves were not supplied with nerve endings. Today, there is the hypothesis that the discs are supplied with nerves, and that direct pain may occur as a result of degenerative changes to them.
When we are young and healthy, the interior of the disc (nucleus pulposus) remains is at full cushioning volume and the outer layers (annulus fibrosus) are strong and tear-free. However, certain changes occur to these discs, either due to the effects of time or due to injuries such as whiplash and trauma.
Over time, the material that keeps the disc inflated and elevated loses its volume and capacity to retain water. This may cause the disc to shrink and lose its ability to protect the spinal vertebrae and joints.
Over time, the outer envelope of the disc may become frayed and eventually torn to the point that tear open up that are large enough for the material inside the disc to project outward. This condition is known as a disc herniation - or herniated disc. Other medical terms that are used interchangeably to describe a herniated disc condition include a disc protrusion, slipped disc, ruptured disc, and collapsed disc.
Disc Pain: Disc pain described the set of symptoms that occurs when the disc itself is the cause of the pain. Discogenic pain is also known as axial pain.
Pinched Nerve: A pinched nerve is the other type of pain that is related to degenerative disc disease. This is pain that is caused by the disc wall bulging outward - pressing into the spinal nerves, or the disc tearing and ejecting its nucleus material into the spinal nerves. Many of these spinal nerve roots give rise to nerve branches that travel the length of the body or one of the limbs. When the nerve is impacted, it may function differently to cause strange neurologic symptoms (burning or tingling) or eventually suffocate to the point that the structure it supplies becomes unable to function properly. These symptoms may be described as numbness, weakness, or resulting in faulty movement patterns.
Pinch nerve symptoms may be considered to be pretty serious because prolonged compression of the nerves may result in irreversible nerve damage, even after the source of the compression has been fixed.
Pain that is experienced as a result of a pinched nerve is known as radicular pain. Radicular pain, also known as nerve root pain, may be felt near the site of nerve compression, as well as along as the entire pathway of that nerve. This is why radicular pain may be felt along an entire arm or leg. Sciatica is the most common type of radicular pain.
A herniated disc is the most common cause of sciatica. Other causes of sciatica is piriformis syndrome (resulting from muscle tension), spinal arthritis, spinal stenosis, and bone spurs (osteophytes).