Can a Herniated Disc Shrink on Its Own? What MRI Changes Really Mean

If an MRI shows an L4-L5 or L5-S1 herniated disc, one of the first questions is often:

Can the disc actually shrink without surgery?

In some cases, yes.

A lumbar herniated disc can decrease substantially in size over time, and the body may partially or even extensively resorb the herniated material. This process is known as spontaneous disc regression or spontaneous resorption.

Surprisingly, the discs that look most dramatic on MRI are not always the least likely to improve. An extruded disc or sequestered disc fragment may sometimes be more likely to shrink than a smaller contained protrusion.

But this does not mean every herniated disc should simply be left alone.

The more important question is:

What is happening to the nerve while the disc is given time to recover?

Pain may improve while the disc remains visible on MRI. A disc may shrink while numbness takes longer to recover. And if weakness, foot drop or walking difficulty develops, protecting nerve function may become more important than waiting for a better-looking scan.

That is why a useful assessment looks at:

pain + numbness + muscle strength + walking + neurological examination + MRI findings + change over time

rather than disc size alone.

If your main question is about treatment rather than natural regression, read the dedicated Non-Surgical Herniated Disc Treatment in Dubai guide.

Quick Answer: Can a Herniated Disc Shrink Without Surgery?

Yes. Some lumbar herniated discs can shrink or undergo spontaneous resorption without surgical removal.

A 2024 meta-analysis including 31 studies and 2,233 conservatively treated patients reported spontaneous resorption overall in about 70% of the pooled study population.

The likelihood differed substantially by disc type:

• Sequestration: approximately 88%
• Extrusion: approximately 67%
• Protrusion: approximately 38%
• Disc bulge: approximately 13%

These figures describe groups of patients and cannot predict what will happen to one individual patient.

They do, however, demonstrate an important principle:

Disc morphology matters.

An extruded or sequestered fragment may be biologically more exposed to the processes that allow the body to break down and resorb disc material.

The clinical question therefore becomes:

Is this disc suitable for observation—and is the affected nerve remaining stable while recovery occurs?

Your MRI Says L4-L5 or L5-S1: What Should You Look at First?

Do not begin with the number of millimetres.

Instead, ask:

• Is it a bulge, protrusion, extrusion or sequestration?
• Which nerve root is being compressed?
• Does that nerve explain the leg pain or numbness?
• Is muscle strength normal?
• Is walking changing?
• Are the symptoms improving or deteriorating?

If the terminology on your report is confusing, the guide How to Read a Lumbar MRI Report: Disc Bulge, Herniation and Nerve Compression explains the most important MRI terms in more detail.

For a broader introduction to the condition itself, see Lumbar Herniated Disc: Symptoms, Causes and Treatment Options.

What Does It Actually Mean When a Herniated Disc “Shrinks”?

A herniated disc does not usually heal because someone mechanically pushes the disc back into exactly its original position.

Instead, several changes may occur in the exposed disc material.

The fragment may:

• lose water,
• decrease in volume,
• undergo tissue breakdown,
• become exposed to the body's immune response,
• and be partially resorbed.

On a later magnetic resonance imaging scan (MRI), the herniated material may therefore appear smaller.

So when patients say:

“My disc went back into place,”

the more accurate explanation may be:

The herniated fragment regressed or was partially resorbed.

How Does the Body Resorb a Herniated Disc?

A lumbar disc normally exists in an environment with relatively limited direct blood supply.

When disc material escapes farther outside its normal boundaries, particularly into the epidural space, it may become more exposed to surrounding tissue and the immune system.

Several biological mechanisms are thought to contribute to spontaneous regression:

• inflammatory signalling,
• growth of small blood vessels around the fragment,
• migration of immune cells,
• infiltration by macrophages,
• breakdown of disc matrix,
• dehydration of the fragment,
• and gradual reduction in volume.

So inflammation has a complicated role.

It can contribute to nerve-root pain, but components of the inflammatory response may also participate in the process by which exposed disc material is cleared.

This helps explain why different types of herniation can behave very differently over time.

Which Herniated Disc Type Is Most Likely to Shrink?

Understanding four common MRI terms is especially useful.

1. Disc Bulge

A disc bulge usually involves a broad extension of disc tissue beyond its normal margin.

The disc remains relatively contained.

Symptoms may improve substantially without the bulge completely disappearing from MRI.

Large radiological regression appears less common than with extruded or sequestered disc material.

2. Disc Protrusion

A disc protrusion is more focal than a broad bulge, but the base of the displaced material remains relatively broad.

A protrusion can regress.

However, available evidence suggests spontaneous resorption occurs less frequently than with more exposed disc fragments.

3. Disc Extrusion

A disc extrusion occurs when disc material extends farther through the outer disc layers.

This can look more alarming on MRI.

However, because the material is more exposed to surrounding tissues, an extruded disc may have a greater potential for spontaneous regression than a contained protrusion.

4. Sequestered Disc

A sequestered disc occurs when a fragment separates from the parent disc.

The phrase “sequestered fragment” can sound particularly serious when it appears on an MRI report.

Yet this morphology has demonstrated some of the highest spontaneous resorption rates in published research.

This creates an important distinction:

A more dramatic-looking MRI does not automatically mean the disc has less chance of shrinking.

Can a Large Herniated Disc Shrink Naturally?

Yes.

Some large herniated discs can regress substantially.

Patients often assume:

small disc = likely to recover

and:

large disc = surgery

But disc biology is more complicated than that.

A large extruded fragment may be more exposed to the immune and vascular response involved in resorption.

A smaller contained protrusion may have less exposure.

That does not mean large herniations are automatically safer.

Their clinical importance depends on:

• location,
• direction,
• available space around the nerve,
• which nerve root is compressed,
• muscle strength,
• pain and sensory changes,
• and whether neurological function is deteriorating.

Does Herniated Disc Size Determine Whether You Need Surgery?

No.

The number of millimetres written in an MRI report does not determine treatment by itself.

Instead of asking only:

“How big is my disc?”

ask:

Where is it?

Which nerve is it compressing?

Does that nerve explain my symptoms?

Is muscle strength preserved?

Are symptoms getting better or worse?

A relatively small disc herniation in a strategically narrow location can sometimes cause significant nerve compression.

A larger abnormality may produce surprisingly little neurological dysfunction in another patient.

This is why MRI anatomy must be matched with neurological function.

How Long Does It Take for a Herniated Disc to Shrink?

There is no fixed timeline.

Regression may begin during the first several months, and MRI changes may continue for longer.

The 2024 meta-analysis of spontaneous lumbar disc resorption found that much of the observed resorption process occurred within approximately the first six months of conservative treatment.

But this should never be interpreted as:

“Everyone with a herniated disc should wait six months.”

The safe timeline depends on what is happening clinically.

Important questions include:

• Is leg pain decreasing?
• Is numbness shrinking or spreading?
• Is foot strength normal?
• Is the big toe becoming weaker?
• Is walking changing?
• Is foot drop developing?
• Are there emergency neurological symptoms?

A patient who is steadily improving with preserved muscle strength is very different from a patient whose foot is progressively weakening.

Can Pain Improve Before the Disc Shrinks?

Yes.

This is common enough to be an important concept.

A herniated disc can produce symptoms through both:

mechanical compression of the nerve

and:

inflammation around the nerve root.

If nerve-root inflammation improves, leg pain can decrease before substantial MRI regression occurs.

Therefore:

Less pain does not prove the disc has disappeared.

But pain improvement is encouraging when it occurs together with:

• improving mobility,
• reduced leg symptoms,
• stable muscle strength,
• normal walking,
• and gradual return to activity.

Can a Herniated Disc Stay on MRI After the Pain Is Gone?

Yes.

A disc protrusion or residual herniation can remain visible on imaging even when the patient has:

• minimal pain,
• normal walking,
• normal strength,
• good sleep,
• and normal daily function.

This is one of the reasons spine treatment should not focus on creating a “perfect MRI.”

The goal is not necessarily:

Normal scan = success.

A better goal is:

Normal or improving function with a stable nerve and acceptable symptoms.

If the Disc Shrinks, Does the Nerve Recover Immediately?

Not necessarily.

Disc regression and nerve recovery are related but separate processes.

A patient may notice:

leg pain improves first

followed by:

burning and tingling improving

while:

numbness takes longer to recover.

If the nerve has developed motor dysfunction, muscle strength may follow a different recovery timeline altogether.

This is why a smaller disc on MRI does not automatically mean the nerve has fully recovered.

Why Can Numbness Continue After Sciatica Pain Improves?

Pain and sensory nerve dysfunction do not always recover at the same speed.

Inflammation may decrease quickly enough to reduce pain while altered sensation persists.

The important distinction is between:

numbness that is gradually becoming smaller

and:

numbness that is spreading or becoming more pronounced.

Progressively increasing sensory loss deserves reassessment, particularly if weakness is also developing.

If your main symptom is radiating leg pain, read Sciatica Treatment in Dubai: Causes, MRI Diagnosis and Non-Surgical Options.

My Pain Is Better but My Foot Is Weaker—Is That Still Improvement?

Not necessarily.

This is one of the most important situations to recognize.

A patient may say:

“My sciatica is much better, but my foot is starting to feel weak.”

Pain relief alone does not prove neurological recovery.

Motor weakness may appear as:

• difficulty lifting the foot,
• difficulty lifting the big toe,
• difficulty heel walking,
• repeated tripping,
• dragging the foot,
• or a visible change in gait.

In this situation, the important question changes from:

“How much pain do you have?”

to:

“Is the nerve losing motor function?”

For a detailed guide, read Herniated Disc and Foot Weakness: When Does Foot Drop Matter?.

Can an L4-L5 Herniated Disc Shrink?

Yes.

Some L4-L5 disc herniations can regress over time.

But “L4-L5” is only the spinal level.

It does not tell us:

• whether the disc is contained,
• whether it is extruded,
• whether a fragment has migrated,
• whether a nerve is compressed,
• or whether the patient is neurologically stable.

In a common posterolateral L4-L5 herniation, the L5 nerve root may be affected.

Possible findings include:

• pain along the outer leg,
• numbness over the top of the foot,
• altered sensation around the big toe,
• weakness lifting the big toe,
• difficulty lifting the front of the foot,
• difficulty walking on the heel.

The more useful question is therefore not simply:

“Will my L4-L5 disc shrink?”

It is:

“Is my L5 nerve functioning normally while the disc is being managed?”

For a detailed comparison, see L4-L5 & L5-S1 Disc Treatment Without Surgery.

Can an L5-S1 Herniated Disc Shrink?

Yes.

Some L5-S1 disc herniations can also regress spontaneously.

When an L5-S1 herniation affects the S1 nerve root, symptoms may include:

• buttock pain,
• pain down the back of the thigh,
• calf pain,
• numbness toward the outer foot,
• reduced push-off strength,
• or difficulty repeatedly rising onto the toes.

But once again:

L5-S1 is the level—not the treatment decision.

The more meaningful assessment considers:

• disc morphology,
• disc direction,
• nerve compression,
• muscle strength,
• walking function,
• and symptom progression.

Does Sciatica Improve When the Herniated Disc Shrinks?

It can.

If sciatica is caused by inflammation or compression of a lumbar nerve root from a herniated disc, decreasing inflammation and pressure can improve:

• radiating leg pain,
• burning,
• tingling,
• and sometimes numbness.

However, a herniated disc is not the only cause of sciatica.

Other causes may include:

• lumbar spinal stenosis,
• foraminal stenosis,
• spondylolisthesis,
• and other forms of nerve-root compression.

That is why a patient with sciatic pain should not automatically assume that waiting for disc resorption will solve every case.

You can read the dedicated Sciatica Treatment Guide for a broader discussion of these causes.

Do You Need Another MRI to See Whether the Disc Has Shrunk?

Not always.

If symptoms are clearly improving and neurological function is stable, repeat MRI may not be necessary simply to prove that the disc has become smaller.

Useful clinical signs of improvement include:

• less pain traveling into the leg,
• a smaller area of numbness,
• improved walking,
• better sleep,
• increased activity tolerance,
• stable or improving muscle strength.

Repeat MRI may become more useful when:

• symptoms worsen,
• weakness develops,
• symptoms no longer match previous imaging,
• improvement does not occur as expected,
• or updated anatomy is needed before a procedure.

A useful principle is:

MRI should answer a clinical question.

It should not simply be repeated to chase disc size.

Current imaging guidance also generally discourages routine immediate MRI for uncomplicated acute low-back pain or radiculopathy without red flags, while imaging becomes more relevant with progressive neurological findings or when intervention is being considered.

Can You Tell That a Disc Is Shrinking From Symptoms Alone?

No.

Symptoms cannot confirm the actual size of a disc fragment.

Pain may improve because:

• inflammation has decreased,
• nerve sensitivity has changed,
• mechanical irritation has decreased,
• or the disc has genuinely regressed.

But clinical improvement is still important.

The distinction is:

radiological regression = MRI change

while:

clinical recovery = the patient feels and functions better.

You do not necessarily need both to happen at exactly the same time.

Can Exercise Push a Herniated Disc Back Into Place?

That is not an accurate way to describe exercise.

No standard exercise can reliably push an extruded disc fragment mechanically back into the disc.

Appropriate exercise and rehabilitation may instead help improve:

• movement,
• strength,
• spinal tolerance,
• confidence with activity,
• walking,
• and functional recovery.

Spontaneous disc resorption is a biological process, not a mechanical movement performed by one specific exercise.

Claims that a certain movement can “put your disc back in place in a few days” should therefore be treated cautiously.

Can Physiotherapy Make a Herniated Disc Disappear?

Physiotherapy should not be described as a treatment that literally dissolves herniated disc material.

Depending on the patient, rehabilitation may help with:

• movement,
• muscle conditioning,
• functional recovery,
• return to activity,
• and symptom management.

A herniated disc may regress biologically during the same period, but this does not mean physiotherapy itself has dissolved the fragment.

The goal is primarily to help the patient recover, not to produce a specific MRI appearance.

Do Spinal Injections Dissolve a Herniated Disc?

Standard spinal injections should not be described as directly dissolving a herniated disc.

Selected injections may be used in appropriate patients to:

• reduce inflammation around a nerve root,
• control radicular pain,
• and make rehabilitation easier.

That process is different from spontaneous disc resorption.

If you want to understand the full range of non-surgical approaches rather than natural disc regression, read Non-Surgical Herniated Disc Treatment in Dubai.

Does Bed Rest Help a Herniated Disc Shrink?

Prolonged bed rest is not usually the goal for an uncomplicated lumbar herniated disc.

A short reduction in aggravating activity may sometimes be appropriate, but prolonged inactivity can contribute to:

• reduced conditioning,
• muscle weakness,
• reduced mobility,
• and greater difficulty returning to normal life.

The appropriate activity level depends on the individual patient, symptoms and neurological findings.

The aim is not:

“Stay in bed until the disc disappears.”

Can a Herniated Disc Improve Even If It Never Disappears?

Absolutely.

This is one of the most important points in the article.

A patient may still have an abnormal disc on MRI while:

• pain has settled,
• numbness is minimal,
• strength is normal,
• walking is normal,
• and daily life has returned to normal.

This is why the absence of complete radiological regression does not equal treatment failure.

The goal is not to eliminate every age- or injury-related change visible on imaging.

The goal is to restore function and protect neurological health.

Does a Herniated Disc That Does Not Shrink Need Surgery?

No.

A disc remaining visible on MRI does not automatically mean surgery is required.

One patient may have a persistent MRI abnormality but no important symptoms.

Another patient may require earlier surgical evaluation because neurological weakness is worsening.

The treatment decision therefore should not be based on:

“Did the disc disappear?”

It should be based on:

Is the nerve stable?

Is the patient improving?

Is weakness present or progressing?

Does the imaging explain the clinical findings?

Has appropriate non-surgical care failed when it was suitable?

For a dedicated discussion of surgical indications, read When Does a Herniated Disc Require Surgery? Warning Signs to Know.

When Can a Herniated Disc Be Given Time to Improve?

A period of structured non-surgical management may be considered when appropriate, particularly when:

• muscle strength is preserved,
• neurological findings are stable,
• there is no progressive weakness,
• emergency warning signs are absent,
• symptoms are stable or improving,
• and clinical assessment supports conservative management.

The possibility of spontaneous disc regression is one reason why MRI appearance alone should not automatically determine surgery.

But observation is not the same as ignoring the condition.

The patient and nerve still need to be followed clinically.

When Should You NOT Wait for the Disc to Shrink?

Evidence that disc herniations can regress naturally should never be used to justify waiting when neurological function appears to be deteriorating.

Seek prompt medical assessment if you develop:

• new leg weakness,
• new foot weakness,
• worsening weakness,
• difficulty lifting the foot,
• difficulty lifting the big toe,
• foot drop,
• repeated tripping,
• a clear change in walking,
• or progressively increasing numbness.

Seek emergency medical care for symptoms such as:

• new bladder-control problems,
• new bowel-control problems,
• significant new difficulty urinating together with neurological symptoms,
• numbness around the groin, inner thighs or saddle region,
• or severe or rapidly progressive weakness.

In these situations, the priority is no longer:

“Will my disc shrink in the next few months?”

It is:

“Is neurological function at risk now?”

Major weakness and new bladder or bowel dysfunction are established warning signs requiring urgent medical attention.

7 Questions That Matter More Than the Number of Millimetres on Your MRI

If your report says you have a herniated disc, ask these questions before becoming focused on size alone.

1. What Type of Disc Problem Is It?

Is it:

• a bulge,
• protrusion,
• extrusion,
• or sequestration?

This can affect the likelihood of spontaneous regression.

2. Which Level Is Involved?

Is the abnormality at:

• L4-L5,
• L5-S1,
• or another level?

The level is important, but it does not determine treatment by itself.

3. Which Nerve Is Being Compressed?

Does the disc actually compress a nerve?

More importantly:

Does that nerve explain the patient's symptoms?

4. Is Muscle Strength Normal?

Can the patient:

• lift the foot,
• lift the big toe,
• walk on the heel,
• and repeatedly rise onto the toes?

5. What Is Happening to the Numbness?

Is it:

• becoming smaller,
• staying the same,
• or spreading?

6. Has Walking Changed?

Look for:

• repeated tripping,
• dragging the foot,
• reduced push-off,
• difficulty climbing stairs,
• or a new change in gait.

7. Are Symptoms Improving or Deteriorating?

An MRI is a snapshot.

The progression of neurological symptoms tells us what is happening to the patient between scans.

Herniated Disc Evaluation With Op. Dr. Fatih Kırar in Dubai and Istanbul

When a patient has a herniated disc, the purpose of specialist assessment is not simply to read L4-L5, L5-S1 or a disc measurement from the report.

The more useful questions are:

Is the disc genuinely compressing a nerve?

Does that nerve match the pain or numbness pattern?

Is muscle strength preserved?

Can the disc safely be observed while natural recovery occurs?

Or is there a neurological reason not to wait?

Op. Dr. Fatih Kırar evaluates herniated disc, sciatica, nerve-root compression and spine conditions in Dubai and Istanbul.

Herniated Disc Evaluation in Dubai – DRFK

In Dubai, patients can be evaluated at DRFK Turkish Medical Center in Jumeirah 3.

Depending on the clinical situation, assessment may include:

• reviewing pain distribution,
• mapping numbness,
• testing leg, foot and toe strength,
• assessing walking,
• reviewing previous MRI or CT images,
• and correlating the disc abnormality with the affected nerve.

Patients can also explore the DRFK Spine Treatment Program and the dedicated Herniated Disc Treatment in Dubai service.

If your MRI shows a disc but you do not know whether it can safely be observed, nerve function may be more important than disc size alone.

Book a spine assessment with Op. Dr. Fatih Kırar at DRFK Dubai

Herniated Disc Evaluation in Istanbul

Op. Dr. Fatih Kırar also evaluates patients at his private clinic in Şişli, Istanbul.

Patients can bring or share previous:

• MRI scans,
• CT scans,
• X-rays,
• reports,
• and information about previous treatment.

The imaging can then be reviewed alongside:

• pain distribution,
• sensory changes,
• muscle strength,
• walking,
• and neurological examination findings.

This is particularly useful when an MRI shows abnormalities at several levels, because the biggest-looking disc is not always the one causing the symptoms.

Patients travelling internationally can also contact the Istanbul team before their visit and provide available imaging.

Contact Op. Dr. Fatih Kırar's Istanbul clinic

Frequently Asked Questions About Herniated Disc Regression

Can a Herniated Disc Heal on Its Own?

Some lumbar herniated discs can decrease substantially in size without surgical removal. This process is called spontaneous regression or spontaneous resorption.

Can a Herniated Disc Completely Disappear on MRI?

It can happen in some patients, particularly with certain extruded or sequestered fragments. However, complete disappearance cannot be guaranteed and is not required for clinical recovery.

What Type of Herniated Disc Is Most Likely to Shrink?

Published evidence generally shows higher spontaneous regression rates in sequestered and extruded discs than in protrusions and broad disc bulges.

Can a Large Herniated Disc Shrink Without Surgery?

Yes. Some large extruded or sequestered herniations can regress substantially. Size alone does not determine the likelihood of regression or the need for surgery.

How Long Does It Take for a Herniated Disc to Shrink?

There is no fixed timeline. Much of the spontaneous resorption observed in published studies occurs during the first several months, but individual recovery varies.

Does Less Pain Mean My Disc Is Shrinking?

Not necessarily. Pain may improve because inflammation around the nerve decreases even when MRI still shows disc material.

Can a Disc Shrink While Numbness Remains?

Yes. Sensory recovery may be slower than pain recovery. Increasing numbness or new weakness, however, should be reassessed.

Can an L4-L5 Herniated Disc Shrink?

Yes. Some L4-L5 herniations regress naturally. Whether observation is appropriate depends on disc morphology, the L5 nerve and neurological findings.

Can an L5-S1 Herniated Disc Shrink?

Yes. Some L5-S1 herniations can also regress. The decision should be based on nerve function and clinical progression rather than the level name alone.

Does a Herniated Disc “Go Back Into Place”?

Not necessarily. The more accurate explanation is often that the exposed fragment loses volume and is partially broken down and resorbed.

Do I Need Another MRI to Know Whether My Disc Is Healing?

Not always. If symptoms and neurological function are clearly improving, repeat MRI may not be necessary solely to demonstrate disc shrinkage.

Can Exercise Put a Herniated Disc Back Into Place?

No exercise can reliably push extruded disc material back into the disc. Exercise and rehabilitation are used primarily to improve movement, strength and function.

Does Physiotherapy Dissolve a Herniated Disc?

No. Physiotherapy does not literally dissolve disc tissue. It can support functional recovery while spontaneous resorption may occur biologically.

Does Every Herniated Disc Need Surgery?

No. Many patients can be managed without surgery. The decision depends on symptoms, neurological examination, nerve compression, progression and response to appropriate conservative care.

When Should I Stop Waiting for a Herniated Disc to Improve?

New or progressive weakness, foot drop, worsening walking ability or emergency neurological symptoms are reasons to seek faster medical assessment rather than continuing to wait for spontaneous regression.

The Bottom Line: Yes, a Herniated Disc Can Shrink but Nerve Function Matters More Than the MRI

Some lumbar herniated discs can shrink substantially or undergo spontaneous resorption over time.

This appears to occur more frequently in extruded and sequestered disc herniations than in contained protrusions and broad disc bulges.

But the most important question should not be:

“Has my disc disappeared from the MRI?”

Ask instead:

Is my leg pain improving?

Is the numbness becoming smaller or spreading?

Can I lift my foot and big toe normally?

Can I walk on my heel and rise onto my toes?

Has my walking changed?

Is weakness developing?

Does the disc on MRI actually compress the nerve that explains my symptoms?

A disc can remain visible on MRI while the patient returns to normal life.

A disc can become smaller while the affected nerve still needs time to recover.

That is why the real goal is not a perfect scan.

The goal is to:

protect nerve function, reduce symptoms, restore movement, and determine when the body can safely be given time to recover—and when waiting is no longer the right choice.

Have an L4-L5 or L5-S1 Herniated Disc? Get the Nerve, Not Just the MRI, Evaluated

If your MRI shows an L4-L5 or L5-S1 disc herniation, especially when pain travels into the leg or foot or is accompanied by numbness, weakness or a change in walking, a neurological spine assessment can help determine whether the condition is suitable for observation and non-surgical care or requires faster evaluation.

Op. Dr. Fatih Kırar evaluates herniated disc, sciatica and nerve compression in Dubai at DRFK Turkish Medical Center and at his private clinic in Istanbul, correlating MRI findings with symptoms, strength and neurological function rather than treating the scan alone.

Dubai – DRFK Turkish Medical Center

Book your herniated disc and spine assessment at DRFK Dubai

Istanbul – Op. Dr. Fatih Kırar Clinic

Book or request an evaluation with Op. Dr. Fatih Kırar in Istanbul

Medical note: This article is for general educational purposes. Individual imaging findings, symptoms and treatment needs vary. New bladder or bowel dysfunction, saddle-area numbness or rapidly progressive weakness requires urgent medical evaluation.