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The C5-C6 Cervical Segment: Disc Herniation, Foraminal Stenosis, and MRI Findings Explained

Written by Ifije Ohiorhenuan, MD, PhD — Board-Certified Spine Surgeon. Last updated 2026-06-20.

A C5-C6 disc herniation means the disc between the fifth and sixth cervical vertebrae is bulging or protruding, but the finding only matters clinically if it matches your symptoms and shows meaningful nerve or spinal cord compression.

In my practice, the first thing I tell patients is that a C5-C6 finding on MRI is not a diagnosis by itself. It is one piece of the puzzle.

MRI means magnetic resonance imaging. It is a scan that shows discs, nerves, the spinal cord, and other soft tissues. MRI reports can sound scary. Words like “herniation,” “stenosis,” and “cord flattening” need careful interpretation.

The key question is simple:

Does the C5-C6 MRI finding match your symptoms, your exam, and the exact nerve or spinal cord area involved?

What Is the C5-C6 Segment?

Where C5-C6 Is Located

C5-C6 is in the lower part of your neck.

Your cervical spine is the neck part of your spine. It has seven bones called cervical vertebrae. Vertebrae are the bones that stack to form the spine.

C5 is the fifth cervical vertebra. C6 is the sixth cervical vertebra. The C5-C6 segment is the level between these two bones.

What Structures Are at This Level

The C5-C6 level is not just a “disc.” It is a motion segment made of bones, joints, ligaments, a disc, the spinal canal, and nerve passageways.

At C5-C6, the main structures include:

  • The C5 and C6 vertebrae: These are the neck bones at this level.
  • The C5-C6 disc: A disc is a cushion between two spine bones. It helps absorb force and allows motion.
  • Facet joints: These are small joints in the back of the spine. They help guide neck motion.
  • Ligaments: Ligaments are strong bands of tissue that help hold bones together.
  • Spinal canal: This is the central tunnel inside the spine.
  • Neural foramina: Neural foramina are small side openings where nerves exit the spine.
  • Spinal cord: The spinal cord is the main nerve cable that runs from the brain through the spinal canal.
  • Exiting nerve roots: Nerve roots are branches that leave the spinal cord and travel into the arms and body.

At C5-C6, the nerve that exits through the side opening is usually the C6 nerve root.

Why C5-C6 Commonly Shows Up on MRI Reports

C5-C6 is one of the most common neck levels to show wear-and-tear change on MRI.

This level moves often. It also carries stress during daily neck motion. Over time, the disc can lose height. Joints can enlarge. Bone spurs can form. A bone spur is extra bone that develops along the edge of a joint or disc space.

Common MRI phrases at C5-C6 include:

  • Disc bulge: A broad extension of the disc beyond its usual edge.
  • Disc herniation: A more focused push-out of disc material.
  • Disc protrusion: A type of herniation where disc material sticks out in a focused area.
  • Disc osteophyte complex: A mix of disc bulging and bone spur formation.
  • Foraminal stenosis: Narrowing of the nerve exit tunnel.
  • Canal stenosis: Narrowing of the central spinal canal.
  • Cord compression: Pressure on the spinal cord.
  • Uncovertebral hypertrophy: Enlargement of small side joints in the neck called uncovertebral joints.

Common does not mean unimportant, but common also does not mean dangerous by itself.

Many people have disc bulges, disc degeneration, or foraminal narrowing on MRI without having symptoms from that exact level. That is why the MRI report must be matched to your symptoms and neurologic exam. A neurologic exam is a physical exam that checks strength, feeling, reflexes, balance, and coordination.

What a C5-C6 Disc Herniation Means

A C5-C6 disc herniation means disc material has moved beyond its usual border between the C5 and C6 bones.

This may or may not matter. It depends on what the disc is touching.

What I look for on MRI is not just whether the disc is herniated, but whether it is contacting the nerve root or spinal cord in a way that matches the patient’s symptoms.

You can learn more about the broader condition here: cervical disc herniation.

Disc Bulge vs Disc Herniation at C5-C6

These words sound similar, but they are not exactly the same.

  • Disc bulge: The disc extends outward in a broad way.
  • Disc herniation or protrusion: Disc material pushes out in a more focused area.
  • Disc osteophyte complex: There is both disc change and bone spur formation.

Think of the disc as a cushion. Over time, the cushion can flatten, bulge, or develop a more focused protrusion. The important question is what that protrusion is touching.

A small disc bulge that does not touch a nerve or the spinal cord may be an age-related finding. A more focused herniation that presses on a nerve root may explain arm pain if the pattern fits.

Central vs Foraminal C5-C6 Disc Herniation

A C5-C6 herniation can point in different directions.

A central herniation points toward the middle of the spinal canal. The spinal canal is the main tunnel that holds the spinal cord. A central herniation may narrow the canal. If it is large enough, it may affect the spinal cord.

A foraminal herniation points toward the neural foramen. The neural foramen is the side tunnel where a nerve root exits. At C5-C6, this often involves the C6 nerve root.

A paracentral herniation sits between the center and the side. It may affect the spinal canal, the nerve root area, or both.

What Is C5-C6 Foraminal Stenosis?

C5-C6 foraminal stenosis means the nerve exit opening at C5-C6 is narrowed.

At C5-C6, foraminal stenosis often involves the C6 nerve root. This is the nerve that commonly exits through that opening.

Foraminal stenosis can come from several changes, including:

  • Disc bulge or disc herniation
  • Bone spurs
  • Uncovertebral joint enlargement
  • Facet arthritis, which means wear-and-tear change in the small spine joints
  • Loss of disc height

When the disc loses height, the nerve tunnel can become smaller. Bone spurs can also grow into the tunnel.

When I see C5-C6 foraminal stenosis, I ask whether the patient’s symptoms sound like C6 nerve irritation or whether the narrowing may simply be an age-related finding.

Foraminal stenosis means the tunnel is narrowed. It does not automatically prove the nerve is irritated enough to cause symptoms.

Symptoms That May Come From C5-C6

C5-C6 findings can cause symptoms if they irritate or compress the right structure.

The finding matters most when the MRI abnormality, the side of the symptoms, and the neurologic exam all point to the same nerve root.

C6 Nerve Root Symptoms

If the C6 nerve root is irritated or compressed, it can cause cervical radiculopathy. Cervical radiculopathy means symptoms from an irritated or compressed nerve root in the neck.

C6 nerve root symptoms may include:

  • Neck pain that travels into the shoulder or arm
  • Pain that moves toward the thumb or index finger
  • Numbness or tingling in a C6-type pattern
  • Weakness with elbow flexion in some cases
  • Weakness with wrist extension in some cases
  • Changes in the biceps reflex or brachioradialis reflex on exam

The biceps reflex is the reflex checked near the front of the elbow. The brachioradialis reflex is checked near the thumb side of the forearm.

Symptom patterns are helpful, but they are not perfect. Real patients do not always read the textbook.

Pain from C5-C6 can overlap with nearby levels. For example, symptoms from the C4-C5 segment or the C6-C7 segment can sometimes look similar.

Neck Pain Alone Is Less Specific

Neck pain by itself is less specific.

It can come from many structures, such as:

  • Discs
  • Facet joints
  • Muscles
  • Ligaments
  • Posture-related strain
  • Other non-spine causes

A C5-C6 disc herniation may be related to neck pain in some cases. But neck pain alone does not prove that the disc is the source.

When C5-C6 Can Affect the Spinal Cord

A central C5-C6 problem can matter more if it narrows the spinal canal and compresses the spinal cord.

This is different from a pinched nerve root.

Myelopathy means spinal cord dysfunction. In the neck, it is often called cervical myelopathy.

Symptoms that may suggest spinal cord involvement include:

  • Hand clumsiness
  • Trouble with buttons, handwriting, or fine motor tasks
  • Balance difficulty
  • Leg stiffness or heaviness
  • Falls
  • Worsening coordination
  • Weakness in the arms or legs
  • Bowel or bladder control changes in more advanced cases

Spinal cord symptoms are a different category than arm pain from a single pinched nerve.

Learn more about cervical spinal stenosis and myelopathy.

How Spine Surgeons Decide Whether a C5-C6 Finding Matters

The MRI Finding Must Match the Symptoms

The finding matters most when the side, level, severity, and symptom pattern line up.

A spine surgeon does not look at the MRI report in isolation. The report is compared with the story, symptoms, and exam.

Key questions include:

  • Does the MRI show right-sided, left-sided, or central compression?
  • Do the symptoms match the same side?
  • Is the affected nerve root consistent with the pain or numbness pattern?
  • Is there weakness?
  • Is there a reflex change?
  • Is there spinal cord compression?
  • Is there spinal cord signal change, which means the cord itself looks irritated or injured on MRI?
  • Are there other levels, such as C4-C5 or C6-C7, that may also be involved?

For example, severe right C5-C6 foraminal stenosis may matter more if the person has right-sided pain into the thumb, matching weakness, or a matching reflex change.

But if symptoms are on the other side, or if the pain pattern does not fit, the finding may be less clear.

Mild, Moderate, and Severe Findings

MRI reports often use words like mild, moderate, and severe.

These words are useful, but they are partly interpretive. One radiologist may call a finding moderate. Another may call a similar finding moderate-to-severe.

A simple way to think about it:

  • Mild: Usually small narrowing or contact. Often not urgent by itself.
  • Moderate: More meaningful narrowing. The clinical match becomes important.
  • Severe: More likely to be clinically important, especially if symptoms or neurologic deficits match.

A neurologic deficit means a problem found on exam, such as weakness, loss of feeling, abnormal reflexes, or coordination trouble.

“Severe” on an MRI report does not automatically mean emergency surgery, but it does deserve careful clinical interpretation.

Not sure whether your C5-C6 MRI finding explains your symptoms? A SpineClarity written MRI/case review can help translate the report into plain language and suggest a general next-step category.

Common Treatments for C5-C6 Disc Herniation or Foraminal Stenosis

Treatment depends on the full picture. It is not based on the MRI phrase alone.

In my practice, surgery is usually not based on the MRI report alone. It is based on the combination of symptoms, neurologic findings, imaging severity, and how the patient has responded to appropriate non-surgical care.

Non-Surgical Treatment

Many patients with cervical radiculopathy improve without surgery, especially when there is no progressive weakness or spinal cord problem.

Non-surgical care may include:

  • Activity modification: Changing certain activities for a period of time.
  • Anti-inflammatory medication: Medicine used to reduce inflammation, when medically appropriate.
  • Physical therapy: Guided exercise and movement treatment.
  • Nerve pain medication: Medication aimed at nerve-related pain in selected patients.
  • Cervical traction: A therapy that gently unloads the neck in selected cases.
  • Epidural steroid injection: An injection around irritated spinal nerves to reduce inflammation.
  • Selective nerve root block: An injection aimed near a specific nerve root.

These options are not right for everyone. The choice depends on the symptoms, medical history, exam findings, and imaging.

When Surgery May Be Discussed

Surgery may enter the conversation when there is:

  • Persistent arm pain despite appropriate non-surgical care
  • Progressive neurologic weakness
  • Severe nerve compression that matches symptoms
  • Spinal cord compression with signs of myelopathy
  • Function-limiting symptoms that correlate with imaging

The goal of surgery, when appropriate, is usually to take pressure off the nerve root or spinal cord.

Common Surgical Options at C5-C6

Common surgical options for selected C5-C6 problems include:

  • Anterior cervical discectomy and fusion, or ACDF: A surgery from the front of the neck. The damaged disc is removed, the nerve or spinal cord is decompressed, and the bones are fused together.
  • Cervical disc replacement: A surgery from the front of the neck where the disc is removed and replaced with an artificial disc in selected patients.
  • Posterior cervical foraminotomy: A surgery from the back of the neck that opens the nerve exit tunnel in selected foraminal cases.

No single surgery is best for every C5-C6 problem. The right option depends on the exact anatomy, symptoms, nerve or cord compression, and patient-specific factors.

What Your MRI Report May Say at C5-C6 — Plain-Language Translations

MRI phrase Plain-language meaning Why it may or may not matter
“C5-C6 disc herniation” Disc material is pushing out beyond its usual border between C5 and C6. It matters most if it presses on the C6 nerve root or spinal cord in a way that matches symptoms.
“C5-C6 disc osteophyte complex” There is a mix of disc bulging and bone spur formation. This is common with wear-and-tear change. It may matter if it narrows the canal or foramen.
“Moderate bilateral foraminal stenosis” Both nerve exit tunnels are moderately narrowed. “Bilateral” means both sides. It may matter if symptoms involve one or both C6 nerve roots. It may also be an imaging finding without clear symptoms.
“Severe right foraminal narrowing” The right nerve exit tunnel is very narrowed. It deserves careful review, especially if right-sided C6 symptoms or weakness are present. It does not automatically mean surgery.
“Mild canal stenosis” The central spinal canal is mildly narrowed. Mild narrowing is often not urgent by itself, but symptoms and spinal cord findings still matter.
“Cord flattening” The spinal cord shape is being pressed or indented. This is more important if there are signs of myelopathy, cord signal change, or worsening neurologic function.
“No cord signal abnormality” The spinal cord does not show abnormal internal signal on MRI. This can be reassuring, but it does not replace symptom and exam review.
“Uncovertebral hypertrophy” Small side joints in the neck are enlarged. This can narrow the foramen and may contribute to nerve root irritation if the clinical pattern matches.

When to Seek Urgent Medical Care

Seek urgent medical care now if you have new or worsening arm or hand weakness, trouble walking or balancing, loss of hand coordination, new bowel or bladder control problems, numbness in the groin/saddle area, fever with severe neck pain, recent major trauma, or symptoms that are rapidly worsening. SpineClarity’s written MRI review is not emergency care.

These symptoms do not mean every MRI finding is dangerous. They do mean the situation needs prompt medical attention.

Getting a Clear Interpretation of Your C5-C6 MRI

A C5-C6 MRI report can be hard to read on your own.

A written MRI/case review can help you understand:

  • Whether the C5-C6 finding likely matches your symptoms
  • Whether the report suggests nerve root compression
  • Whether the report suggests spinal cord compression
  • Whether the finding may be more age-related
  • What general next-step category may make sense
  • What questions to ask your treating clinician

If your MRI report mentions a C5-C6 disc herniation, foraminal stenosis, or nerve compression and you are not sure what it means, SpineClarity can provide a written MRI/case review from a board-certified spine surgeon. You upload your symptoms, MRI report, and relevant records, and receive a plain-language interpretation with a suggested next-step category. This is not emergency care and does not replace an in-person physician relationship.

FAQ

Is a C5-C6 disc herniation serious?

It can be serious, but it is not automatically serious.

A C5-C6 disc herniation matters most if it compresses the C6 nerve root or the spinal cord and matches your symptoms or exam findings. Many disc findings are age-related and may not be the main pain source.

What nerve is affected by a C5-C6 disc herniation?

At C5-C6, the nerve most often involved is the C6 nerve root.

If the herniation is central, it may affect the spinal canal or spinal cord instead of only the nerve exit tunnel.

Can C5-C6 cause pain into the arm or hand?

Yes, it can.

If the C6 nerve root is irritated, pain may travel from the neck into the shoulder, arm, forearm, thumb, or index finger. Numbness, tingling, weakness, or reflex changes can also occur.

The pattern is helpful, but it is not perfect.

What does C5-C6 foraminal stenosis mean?

C5-C6 foraminal stenosis means the nerve exit tunnel at C5-C6 is narrowed.

This tunnel is where the C6 nerve root usually exits. Narrowing may come from disc bulging, bone spurs, joint enlargement, or loss of disc height.

It does not automatically prove the nerve is damaged or causing symptoms.

Does severe C5-C6 foraminal stenosis mean I need surgery?

Not always.

Severe foraminal stenosis deserves careful interpretation. It is more likely to matter if your symptoms, weakness, numbness, or reflex changes match the C6 nerve root on the same side.

Surgery is usually discussed when symptoms are persistent and disabling, weakness is worsening, or there is significant matching compression.

Can a C5-C6 problem cause headaches?

Some neck conditions can contribute to headaches.

But a C5-C6 MRI finding by itself does not prove it is the source of headaches. Headaches can come from many causes. Lower-neck findings are less specific for headache than some upper-neck problems.

What is the difference between C5-C6 canal stenosis and foraminal stenosis?

Canal stenosis means narrowing of the central spinal canal. This is the tunnel where the spinal cord sits.

Foraminal stenosis means narrowing of the side opening where a nerve root exits.

At C5-C6, canal stenosis may matter if it affects the spinal cord. Foraminal stenosis may matter if it affects the C6 nerve root.

What symptoms suggest spinal cord involvement rather than just a pinched nerve?

Spinal cord involvement may cause:

  • Hand clumsiness
  • Trouble with buttons or handwriting
  • Balance problems
  • Trouble walking
  • Falls
  • Leg stiffness or heaviness
  • Worsening coordination
  • Bowel or bladder control changes in more advanced cases

These symptoms are different from pain down one arm from a single pinched nerve.

Can C5-C6 findings be present without symptoms?

Yes.

Disc degeneration, disc bulges, protrusions, and foraminal narrowing can appear on MRI in people who do not have symptoms from that level.

That is why clinical correlation matters. Clinical correlation means comparing the MRI to your symptoms, exam, and history.

How do doctors decide if C5-C6 is really the pain generator?

Doctors look for a match.

They compare:

  • The side of symptoms
  • The pain, numbness, or tingling pattern
  • Strength testing
  • Reflexes
  • MRI findings
  • Whether the nerve root or spinal cord is compressed
  • Whether nearby levels may also explain symptoms

C5-C6 is more likely to be the pain generator when these pieces point to the same level and same side.

If you want a surgeon’s written explanation of how your C5-C6 MRI findings fit your symptoms, you can request a SpineClarity MRI/case review.

Related reading

References

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