What Causes Sciatica?
Understanding the root causes of sciatic nerve pain is essential for effective treatment. Learn about the most common conditions that lead to sciatica and how they affect your body.
Understanding Sciatic Nerve Compression
Sciatica occurs when the sciatic nerve becomes compressed or irritated. The sciatic nerve is the largest nerve in your body, running from your lower back through your hips and buttocks and down each leg.
90%
of sciatica cases are caused by herniated discs
L4-L5, L5-S1
are the most commonly affected spinal levels
40-50
years old is the typical age when sciatica first occurs
Most Common Causes of Sciatica
Herniated Disc
Most Common (90%)When the soft center of a spinal disc pushes through a crack in the tough exterior casing, it can press on the sciatic nerve roots.
Key Points:
- Also called slipped or ruptured disc
- Most common in L4-L5 and L5-S1 levels
- Can occur from sudden movement or gradual wear
- May cause both back and leg pain
Spinal Stenosis
Common in Older AdultsNarrowing of the spinal canal that puts pressure on the nerves, including the sciatic nerve roots.
Key Points:
- Usually develops gradually with age
- Caused by bone spurs, thickened ligaments
- May cause pain when walking (neurogenic claudication)
- Often improves when sitting or leaning forward
Spondylolisthesis
5-10% of CasesA condition where one vertebra slips forward over the vertebra below it, potentially pinching nerve roots.
Key Points:
- Can be congenital or develop with age
- May result from stress fractures
- Graded from 1 (mild) to 4 (severe)
- Often occurs at L5-S1 level
Piriformis Syndrome
Less CommonThe piriformis muscle in the buttocks irritates or compresses the sciatic nerve that runs beneath it.
Key Points:
- More common in women
- Can result from muscle spasm or tightness
- May be triggered by sitting or hip rotation
- Often confused with other sciatica causes
Pregnancy-Related
Up to 30% of Pregnant WomenHormonal changes, weight gain, and fetal positioning can compress the sciatic nerve during pregnancy.
Key Points:
- Usually occurs in second or third trimester
- Often resolves after delivery
- Caused by pelvic changes and baby's position
- Safe treatment options are limited
Trauma/Injury
Acute CasesDirect injury to the lower back, pelvis, or buttocks can damage or irritate the sciatic nerve.
Key Points:
- Car accidents, falls, sports injuries
- May cause immediate or delayed symptoms
- Can result in nerve inflammation
- Requires prompt medical evaluation
Risk Factors for Developing Sciatica
Age
Risk increases with age due to wear and tear on spinal structures.
Excess Weight
Extra weight increases stress on the spine and can contribute to disc changes.
Sedentary Lifestyle
Prolonged sitting and lack of exercise can weaken muscles and increase risk.
Occupation
Jobs requiring heavy lifting, twisting, or prolonged sitting increase risk.
Smoking
Smoking reduces blood flow to discs and may accelerate disc degeneration.
Genetics
Family history of back problems can increase susceptibility to sciatica.
🚨 When to Seek Immediate Medical Attention
While most sciatica causes are not serious, certain symptoms require urgent care:
- Loss of bowel or bladder control
- Progressive weakness in the leg
- Numbness in the groin or genital area
- Severe pain following a significant injury