Sciatica is a common symptom of various medical conditions; however, it’s estimated that 90% of cases are due to a herniated disc. The spine consists of vertebrae (individual bones in the spine protecting underlying nerves), nerves, and discs. These discs are made of cartilage, a strong and resilient material that acts as a cushion between each vertebra, allowing the spine to be flexible. A herniated disc occurs when a disc slips out of place, putting pressure on the sciatic nerve.

What is Sciatica?

The term “sciatica” refers to pain that radiates along the path of the sciatic nerve, branching from the lower back through the hips and buttocks and down each leg. Typically, sciatica affects only one side of the body.

According to MedicinePlus, sciatica most often occurs when a herniated disc, a bone spur on the spine, or a narrowing of the spine (spinal stenosis) compresses part of the nerve. This causes inflammation, pain, and often some numbness in the affected leg.

Though the pain associated with sciatica can be severe, most cases resolve with non-surgical treatments within a few weeks. People with severe sciatica related to significant leg weakness or changes in bowel or bladder control may be candidates for surgery.

Causes

Sciatica occurs due to the pinching of the sciatic nerve, usually caused by a herniated disc in the spine or by excessive bone growth (bone spur) on the vertebrae.

Less frequently, a tumor may compress the nerve, or a disease, such as diabetes, may damage the nerve.

Risk Factors

The risk factors for sciatica include:

• Age. Age-related changes in the spine, such as herniated discs and bone spurs, are the most common causes of sciatica.
• Obesity. Excess body weight can increase stress on the spine, contributing to spinal changes that trigger sciatica.
• Occupation. A job that requires twisting your back, carrying heavy loads, or driving for long periods may be related to the development of sciatica, though there’s no conclusive evidence of this link.
• Sedentary lifestyle. People who sit for long periods or have a sedentary lifestyle are more likely to suffer from sciatica than active people.
• Diabetes. This condition, which affects how the body uses blood sugar, increases the risk of nerve damage.

Other Causes of Sciatica Include:

• Lumbar spinal stenosis: narrowing of the spinal cord in the lower back.
• Spondylolisthesis: a condition in which one disc slips over the vertebra below it.
• Tumors within the spine: can compress the sciatic nerve root.
• Infection: eventually affecting the spine.
• Injury: to the spine.
• Cauda equina syndrome: a rare but serious condition affecting the nerves at the lower end of the spinal cord; requires immediate medical attention.
• In many cases of sciatica, there isn’t a single obvious cause.

Pregnancy

While sciatica-like pain can be an issue during pregnancy, between 50% and 80% of women experience back pain during pregnancy.

Certain hormones produced during pregnancy, like relaxin, cause ligaments to loosen and stretch, leading to back pain in some women.

However, sciatica due to a herniated disc is less likely during pregnancy.

Finally, If you want to know more, visit our article on What Are Stem Cells.