Why Does My Herniated Disc Hurt So Much If It’s Not That Big?

A small disc herniation can cause severe pain because the material inside the disc is chemically inflammatory, not inert. When it leaks onto a nerve root, it triggers an intense inflammatory reaction that often causes far more pain than mechanical pressure from the disc’s size alone would explain.

Being told your herniation is “small” while you’re in agonizing pain is confusing, and the mismatch has a specific chemical explanation, not an exaggeration on your part.

The Mechanism

The soft inner material of a disc, called the nucleus pulposus, contains an enzyme called phospholipase A2, along with other inflammatory mediators including cytokines and substance P. Under normal circumstances this material stays contained within the disc. When it herniates and makes contact with a nerve root, it does not simply press against it. Animal research has shown that this material is directly inflammatogenic, meaning it provokes inflammation on contact, independent of mechanical compression. A key study found that blocking phospholipase A2 activity eliminated the heightened pain sensitivity caused by nucleus pulposus material in contact with a nerve root, demonstrating that this chemical pathway, not just physical pressure, is a primary driver of disc herniation pain.

This chemical irritation also disrupts blood flow to the nerve itself, compounding the problem, since nerve tissue depends on a steady blood supply to function normally and recover. A clinical review of chemical radiculitis describes how herniated or degenerated disc material releases a cascade of inflammatory promoters, including phospholipase A2, prostaglandin E2, and cytokines, producing intense chemical irritation of the nerve root that accounts for most of the pain associated with disc herniation, distinct from the mechanical compression itself.

This explains why herniation size and pain severity so often fail to match. A small herniation that leaks a significant amount of this inflammatory material directly onto a nerve root can produce searing pain, while a much larger herniation that never breaches the disc’s outer wall, or that sits away from a nerve, may produce little discomfort at all. Pain severity tracks the chemical and mechanical irritation actually reaching the nerve, not the size of the herniation on an image.

When It’s Something More Serious

Progressive weakness, numbness spreading in the groin or inner thighs, or loss of bladder or bowel control needs emergency evaluation. Pain that is dramatically worsening despite treatment, or accompanied by fever, also warrants prompt medical attention.

How This Gets Addressed

Since much of the pain comes from an inflammatory chemical process, not purely mechanical pressure, treatment addresses both.

Naturopathic medicine evaluates and supports the body’s broader inflammatory and healing capacity, since systemic inflammation can compound the local chemical irritation at the nerve root.

Dry needling reduces the protective muscle guarding that develops around an irritated nerve and increases pressure on the disc further.

Chiropractic care restores mobility in the joints surrounding the disc, reducing the mechanical component of the irritation while the chemical inflammation resolves on its own timeline. Any decision about anti-inflammatory medication or injections should be made with your physician.

You can learn more about our full approach to disc herniation here.

Most patients find their pain eases substantially over several weeks as this chemical irritation naturally resolves, often well before the disc’s position on imaging has changed at all, since the chemical environment around the nerve, not the disc’s shape, is what the acute pain actually tracks.

Written By:

Dr. Jason Winkelmann

Naturopathic doctor, Chiropractor, Chronic Pain Specialist, and Educator

Frequently Asked Questions

Will my pain go away even if the disc itself doesn’t shrink?

Often, yes. Since much of the acute pain comes from chemical inflammation rather than the disc’s physical size, pain frequently improves significantly as that chemical irritation resolves over weeks, even before any meaningful change in the disc’s appearance on a follow-up scan.

Why did anti-inflammatory medication or a steroid injection help my pain?

Corticosteroids work in part by inhibiting phospholipase A2 activity directly, which is the same chemical pathway driving much of the nerve root irritation. This explains why these medications can meaningfully reduce disc herniation pain even when they do nothing to physically move or shrink the disc itself.

Does a small herniation mean I’m likely to recover faster than someone with a large one?

Not necessarily, and the relationship can even run the other way. How much inflammatory material actually reaches the nerve root, and how directly it contacts it, matters more for your pain experience than the herniation’s overall size.