A herniated disc and a painful disc are two different problems.

PRP FOR A HERNIATED OR BULGING DISC

PRP does not fix a herniation that is compressing a nerve root. Growth factors do not pull a fragment back off a nerve. Where the disc itself is the confirmed pain generator, intradiscal PRP (injected into the disc) is an option. Around an irritated root, we use platelet lysate instead of standard PRP. The scan alone will not tell you which problem you have.

Most people who arrive with a disc herniation on a scan want to know if an injection can fix it. The honest answer depends entirely on which of two very different problems you have. The scan alone will not tell you.

Is a herniated disc a nerve problem or a disc problem?

A herniation compressing a nerve root causes radicular pain. That is pain that travels down the leg in a familiar pattern, often with numbness, sometimes with weakness. The disc is where the trouble started. But the pain generator is a nerve that is squeezed and chemically irritated. That is a nerve problem.

Discogenic pain is different. The pain sits in the back itself. It is worse with sitting, bending forward and load. It does not travel along a nerve path. Here the disc itself is the pain generator. Its annulus (the tough outer ring) has torn, and nerve fibers have grown inward into the tear.

These need different treatments. The most common error here is to treat the second as if it were the first, or to treat a picture instead of a person. There is more on PRP for the disc, which covers discogenic pain in detail.

Does a bulging disc on my MRI mean it is causing my pain?

This is where the disc differs from every other structure on this website. It is worth saying plainly: disc abnormalities are extremely common in people with no pain at all. Bulges, protrusions and annular tears show up on the scans of adults with no symptoms. The rates climb steadily with age. By the sixth decade, most pain-free people have something a radiologist will describe.

So a report saying “L4-5 disc bulge with annular fissure” is not a diagnosis. It describes a disc that belongs to someone your age. Whether that disc causes your pain is a clinical question. It is answered by exam and, where it matters, by a diagnostic block. It is not answered by how strong the adjective in the report sounds.

When does a herniated disc need surgery instead of an injection?

Where a fragment is physically pressing on a nerve root, no injectate resolves that. Growth factors do not pull a herniation back off a nerve. Anyone offering to treat a compressive herniation with biology is selling something. We will say so instead of taking the booking.

Three findings stop this conversation entirely and start a surgical one, right away:

• Progressive weakness. A foot that is getting harder to lift, or a leg giving way.
• Bowel or bladder change, or saddle numbness (numbness where you sit). This is an emergency. It means today, not after a course of injections.
• A dense, worsening neurological deficit along one nerve root’s path.

None of those are reasons to be careful. They are reasons to be somewhere else.

Where is PRP injected for a disc problem?

Two different things get called “PRP for a disc”. Mixing them up is how expectations go wrong.

Intradiscal injection places the preparation into the disc itself. It targets the degenerative setting inside a disc that is the confirmed pain generator. A double-blind randomized trial of intradiscal PRP in discogenic low back pain reported improvement over control. The evidence since then has been positive but modest. It comes from small trials, with mixed preparations. Recent evidence-based guidelines for regenerative therapies in the spine treat it as an option in carefully selected patients. They do not treat it as an established one.

Epidural PRP places it around an irritated nerve root, not in the disc. It is emerging as a comparator to epidural steroid in lumbar disc herniation with radicular pain. This is a different treatment with a different target. Where we use a preparation near a nerve, it is platelet lysate, not standard PRP. The reason is what gets physically delivered against nerve tissue, which that page explains.

The two things you can change while this settles

Most herniations improve without an operation. The waiting is easier when there is something to do during it. Two exposures are worth acting on, and one caveat has to come with them.

One analysis pooled 20 Mendelian randomization studies. That design uses genetic variants as stand-ins for lifelong exposure. So it gets closer to cause and effect than ordinary observational work. In the pooled result, smoking initiation carried an odds ratio of 1.22 (95% CI 1.12 to 1.33) for intervertebral disc degeneration, and body mass index 1.26 (1.14 to 1.38). Nicotine is the more urgent of the two. It squeezes the small vessels that feed the vertebral endplate. The endplate is the disc’s only supply line.

The caveat, stated rather than buried: those are figures for disc degeneration, not for whether a herniation shrinks. We have not seen evidence that quitting shrinks an extrusion, and we will not imply it. What the numbers support is the condition of the disc you will still have after this episode passes. The strongest predictor of a disc problem is having had one. So that is not a small thing. The wider version is on the discogenic pain page.

The rule that governs the spine here

Nothing on this site is gated more strictly than the spine. The reason is that spine procedures are easy to sell and hard to judge. We do not inject a level until something has told us it is the right level. Not a scan. A provocation response (pain brought on by testing), a diagnostic block, or a clinical picture that is perfectly clear.

That one rule screens out most of the people who arrive asking for this. It screens them out before they have paid for anything. It is set out in full on the spine and sacroiliac joint. Saying no is not a lesser outcome than treating. It is often the correct one.

Can a herniated disc heal on its own?

A large share of disc herniations shrink on their own over months. The natural course of radicular pain from a contained herniation is truly favorable. Time, a proper loading and behavioral program, and control of the metabolic terrain do more for these patients than anything injected.

That last point is not filler. Insulin resistance and metabolic inflammation damage the disc setting directly. A disc failing in that terrain will keep failing, whatever is put into it. Where the terrain is the problem, treating the terrain is the treatment.

What people ask about a disc on a scan

Can PRP shrink my herniation?

No, and most herniations do not need it to. Nothing injected pulls a fragment back off a nerve, but the natural course of a contained herniation is favorable, and time, loading, the behavioral work and the metabolic terrain carry most people through. If it is contained and the pain is in your back, not your leg, PRP is a possible conversation. A herniation pressing on a root with worsening symptoms is the exception, and it needs a surgical opinion.

For how a painful disc differs from one that only looks bad, read A disc that hurts and a disc that looks bad are not the same disc.

My scan says bulging disc at three levels. Which one is causing it?

Very often none of them, and that is the honest answer. Degenerative changes at several levels are close to universal past middle age. The useful question is not which level looks worst. It is which level, if any, brings on your pain. Finding that takes an exam and sometimes a block.

For how a block identifies the right level, read We do not inject a level until a block has told us it is the right one.

Is a bulging disc the same as a herniated disc?

Not quite, though the words get used interchangeably in reports and talk. A bulge is a broad, even spread of the disc edge. A herniation is material pushed out in one spot. In practice, what matters far more than the word is whether anything is being squeezed and whether the disc causes pain on its own.

I had a discectomy and the pain came back. Is this for me?

Possibly. But the first job is finding out what is causing pain now, which is often not what was operated on. That whole problem is the subject of persistent pain after spine surgery. It starts with taking the problem apart, not treating the scar.

Can PRP heal a bulging disc?

It depends on what the bulge is doing. Bulges are common in people with no pain at all. So the first step is finding out if yours is the source. If the disc itself is the pain generator, PRP placed into the disc is an option. If disc material is pressing on a nerve, PRP will not pull it back off the nerve.

Can an L4-L5 disc bulge get better for good?

Most herniations improve without an operation, and many shrink on their own over months. Time, a proper loading program and control of your metabolic health do more for most people than anything injected. What you can change is the disc you keep afterward. Smoking and higher body weight both raise the odds of disc degeneration. Having had one disc problem is the strongest predictor of another.

Related reading

• PRP for the disc
• Spine and the sacroiliac joint
• Platelet lysate — what we use near a nerve
• Still in pain after back surgery
• PRP for the facet joints
• Metabolic health and tissue repair