Radicular pain is a type of nerve pain that originates from an irritated or compressed spinal nerve root and travels along the path of that nerve into an arm or leg. It’s the sharp, shooting sensation that many people know as sciatica when it affects the lower body, though it can also occur in the neck and upper limbs. Annual prevalence in the general population ranges from about 10% to 25%, making it one of the most common reasons people seek care for back and leg pain.
How Radicular Pain Feels
The hallmark of radicular pain is its quality: sharp, shooting, electric, or shock-like. People often describe it as a bolt of pain that travels from the spine down into the buttock, groin, or leg (in lumbar cases) or into the shoulder, arm, and hand (in cervical cases). It typically radiates in a narrow band, no more than two to three inches wide, along the length of the limb. This is distinctly different from the dull, achy, hard-to-pinpoint pain that comes from muscles, joints, or other soft tissues referring pain to nearby areas.
Alongside the pain itself, you may notice tingling, burning, or prickling sensations in the affected area. Some people develop numbness in a patch of skin supplied by the compressed nerve, and less commonly, weakness or cramping in specific muscles. When these neurological deficits (numbness, weakness, reflex changes) accompany the pain, the broader condition is called radiculopathy. Radicular pain can exist on its own as a purely sensory problem, but it frequently overlaps with these other signs.
What Causes It
The most common cause is a herniated disc pressing on a spinal nerve root. The disc between two vertebrae dries out and develops cracks over time, and eventually the soft inner material can bulge or rupture outward. When this material pushes against a nerve root, it triggers both direct mechanical pressure and a local inflammatory response that irritates the nerve fibers.
Degenerative changes in the spine account for most remaining cases. These include:
- Spinal stenosis: gradual narrowing of the spinal canal that crowds the nerve roots
- Spondylolisthesis: one vertebra slipping forward over the one below it, often driven by disc degeneration and joint instability
- Bone spurs: bony growths from arthritic joints that encroach on the space where nerves exit the spine
- Thickened ligaments: age-related thickening of the ligaments inside the spinal canal
Compression at one level of the spine increases the likelihood that multiple nerve roots are affected, sometimes on both sides. This is why some people experience pain radiating into both legs rather than just one.
Where the Pain Travels
Textbooks often show neat dermatome maps suggesting each nerve root sends pain to a precise strip of skin. Reality is messier. A study of patients with confirmed nerve root problems found that about two-thirds of lumbar cases involved pain patterns that did not follow the expected dermatome. The notable exception is the S1 nerve root, which supplies the back of the thigh, calf, and outer edge of the foot. About 65% of people with S1 radicular pain do feel it in that classic pattern.
For other nerve root levels, the pain can spread more broadly or land in unexpected areas. This means you shouldn’t rule out a nerve root problem just because the pain doesn’t match a textbook diagram, and clinicians typically rely on imaging and physical examination rather than pain location alone to pinpoint the affected level.
How It Differs From Referred Pain
Referred pain and radicular pain both send discomfort away from its source, but they feel different and behave differently. Referred pain, which comes from muscles, joints, or organs, is typically dull, aching, or gnawing. It spreads over a broad, poorly defined area and is not distributed along a nerve path. Radicular pain, by contrast, is sharp and electric, travels in a narrow band down the limb, and often comes with neurological signs like numbness or weakness. Understanding this distinction matters because the two types point to different underlying problems and respond to different treatments.
Diagnosis
Physical examination usually starts with a straight leg raise test: you lie on your back while a clinician lifts one leg. If this reproduces your shooting leg pain, it suggests a lower lumbar nerve root is being stretched over a disc bulge. This test is quite sensitive in younger adults, catching roughly 88% of disc herniations in people under 30, but its accuracy drops steeply with age, falling to around 33% in people over 60. A related test called the slump test, performed while seated, applies tension to nerves across all lumbar levels and appears to be more sensitive than the straight leg raise for detecting disc herniations.
Because no single physical test is definitive, MRI is the standard tool for confirming the cause. It shows disc herniations, stenosis, and other structural problems with high detail. Nerve conduction studies can help when the diagnosis is uncertain or when it’s important to confirm which nerve root is affected before considering a procedure.
Treatment and Recovery
Most radicular pain from a disc herniation improves with time and conservative care. The body gradually reabsorbs the herniated disc material, and the inflammation around the nerve settles. Initial management focuses on staying as active as tolerable, using over-the-counter anti-inflammatory medications, and beginning physical therapy to improve spinal mobility and core stability.
When pain is severe or persists beyond several weeks, steroid injections into the epidural space around the affected nerve root are a common next step. A large review of 90 randomized trials found these injections probably reduce pain and disability in the short term, with about one in four treated patients experiencing meaningful pain relief beyond what a placebo provides. However, the evidence for long-term pain reduction is less convincing, and injections are generally used as a bridge to allow participation in rehabilitation rather than as a standalone cure.
Surgery becomes an option when significant weakness develops, when pain remains disabling despite months of conservative treatment, or when imaging shows a large structural problem that’s unlikely to resolve on its own. The most common procedure is a microdiscectomy, which removes the portion of disc pressing on the nerve. Recovery from this surgery typically involves a few weeks of limited activity followed by a gradual return to normal function.
Red Flags That Need Urgent Attention
A rare but serious complication occurs when a large disc herniation compresses the bundle of nerves at the base of the spinal cord, a condition called cauda equina syndrome. Warning signs include sudden difficulty controlling your bladder or bowels, numbness in the groin or inner thighs (sometimes called “saddle anesthesia”), severe weakness in both legs, or rapidly worsening pain that becomes bilateral. This is a surgical emergency. Decompression within hours gives the best chance of preserving nerve function.