Our spine is a complex anatomy, due to the complexity, there are different kinds of pain cause by different parts of the spine, such as:
- Pain from Facets
- Pain from Discs
- Pain at the End of the Spine
- Pain due to Wear and Tear
Pain from Facets
As we age, we lose height, primarily because the discs that separate the vertebra dry out and shrink. The vertebrae become more closely opposed, and the facets take on undue weight. Facets are designed more to create stability than to bear weight. This excess wear causes them to degenerate, and some arthritic and hurt, at times chronically. As they become arthritic, they may also calcify (harden with deposits of calcium from the body) and become deformed. The excess calcification of these joints may bulge into the spinal canal and foramen, pressing on the nerves there. This may contribute to spinal stenosis, the narrowing of spinal canal.
Pain from Discs
Discogenic pain comes from a tear in the annulus, with no disc material oozing out onto a spinal nerve. This kind of pain usually is described as deeper than facet pain, but the two frequently coexist. Discs are deeper in the spinal structure than the facets and pain from them cannot easily be provoked by poking the area around the spine. Both facet and discogenic pain may be one-sided but often affect both sides of the back.
Lumbar-disc-related pain (either discogenic pain or pain from disc herniation) is usually worse during the day. It may exist at night and impair sleep. Many postures and activities make it worse: standing, walking, sitting, rising from a bent position, and bending down. Less commonly, lying in bed, with the spine curving into the mattress, may irritate the torn disc or a lumbar nerve compromised by a herniated disc. Anything that puts vertical or bending-related stress of a degenerated, painful disc may worsen the pain.
Cervical-disc-related pain is worse at night because you turn your head while you sleep. It may also cause pain during the day when you turn your head to look around. When your head bounces around on your neck, such as when you are riding in a car over a rough road, it may also cause pain if you have cervical disc problems.
Thoracic-disc-related pain is rare. When it does not occur, it may cause pain in he back or even travel partway around the chest along a rib. Thoracic disc herniation sometimes results in pain that may be confused with other ailments, like heart disease or reflux of the oesophagus.
Pain at the End of the Spine
The sacrum itself is rarely a cause of pain unless it is fractured or its connection to the lumbar spine is altered. In people with normal bones, sacral fracture may occur from a severe fall. People with severe osteoporosis can fracture the sacrum even fro minor trauma. Various types of sacral tumours can cause local pain and damage to the nearby nerves that control bowel and bladder.
Pain in the area of the sacrum also occurs after fusion surgery in which the lumbar spine is surgically fused to the sacrum at L5-S1. Sacral pain following this type of fusion is perhaps the most common cause of severe chronic sacral pain in the noncancer patient population. Occasionally, sacral pain is due to sore or tight muscles. It may exist while walking, standing, or sitting.
Chronic, severe tailbone – coccyx – pain is rare. This is fortunate, since it is often difficult to treat. Most people with such pain – coccydynia – complain of pain in the tailbone while sitting. It usually develops following a fall on their rear end, usually squarely backward, as on an icy sidewalk. The tailbone can also be invaded by tumours, which cause pain and often bowel dysfunction.
Pain due to Wear and Tear
The spine wears out from stress. The lumbar spine (lower back) supports the most weight and is the most common area for spine-related pain. The are of greatest spinal degeneration is the lower lumbar spine, attached to the fixed pelvis. The lower cervical spine, just above the shoulders, is the second most likely area to degenerate over time. Consequently, the lumbar and cervical areas have the greatest propensity for disc herniations. (The thoracic spine is least likely to cause chronic pain).
The vertebrae themselves may cause pain if fractured by day-to-day trauma, suffer an osteoporotic collapse, are weakened by a blood vessel malformation, or invaded by a tumour. If a piece of fractured vertebra presses on the nerves in the spine or spinal cord, serious, possibly permanent pain, weakness, and numbness or bowel and bladder disturbance may result.
Another problem occasionally seen is a birth defect involving a hole in the bone in the back of the L5 vertebra that disconnects the stabilising facet joint on the side of the defect from the rest of the vertebrae. Over time, this may destabilise the spine, allowing slippage. This type of defect is called spondylolysis. Spondylolisthesis occurs when a vertebral body slips out of place with respect to the one above or below it, causing spinal instability. Think of that gooseneck lamp is no longer in line with the others. This may result in narrowing of the spinal canal and foramen underlying the area of slippage, resulting in pressure on the nerve roots there. This pressure may become a source of chronic pain, weakness, and numbness unless the spinal instability is surgically corrected.
Key Points to Understand Your Back Pain
- The spine is a mechanical masterpiece with many components that can be damaged by injury or aging.
- The lumbar back is the most common site for spinal pain, followed by the cervical area just above the shoulders.
- Most back pain is muscular and improves with time, rest and, at most, conservative treatment.
- Much spine-related pain can be prevented by some lifestyle modifications, such as controlling weight.
- Back pain can also be caused by medical diseases.
Back Pain Specialist
Dr Mathew Tung