The C4-C5 Cervical Segment: What a C4-C5 Disc Herniation Means on MRI
A C4-C5 disc herniation means the disc between the fourth and fifth neck bones is bulging or protruding, but whether it matters depends on whether it is pressing on the spinal cord or the exiting C5 nerve root and whether that matches your symptoms.
If your MRI report mentions “C4-C5 disc bulge,” “C4-C5 foraminal stenosis,” or “C4-C5 spinal canal stenosis,” it can sound alarming. These words describe anatomy. They do not, by themselves, prove the cause of your pain or mean you need surgery.
What Is the C4-C5 Cervical Segment?
The cervical spine is the neck part of your spine. The C4-C5 cervical segment is one motion level in the neck.
Think of C4-C5 as one “joint level” in the neck. It has a disc in the front, small joints in the back, a tunnel for the spinal cord, and side openings where nerves exit.
The C4-C5 level includes:
- The C4 vertebra, which is the fourth neck bone
- The C5 vertebra, which is the fifth neck bone
- The C4-C5 disc, which is the cushion between C4 and C5
- The facet joints, which are small paired joints in the back of the spine
- The spinal canal, which is the main tunnel for the spinal cord
- The neural foramina, which are side openings where nerves leave the spine
- The C5 nerve roots, which are nerves that exit at this level
The spinal cord is the main nerve cable that runs from the brain through the neck and back. At C4-C5, the spinal cord runs through the central canal.
The C5 nerve root exits through the C4-C5 foramen. A nerve root is the first part of a spinal nerve as it leaves the spinal cord area.
For upper neck anatomy nearby, you may also see references to the C2-C3 and C3-C4 upper cervical segments.
What Does a C4-C5 Disc Herniation Mean?
A disc herniation means disc material is pushing beyond its usual border. The disc is like a cushion between two bones. When part of it pushes backward or sideways, it may narrow space around nerves or the spinal cord.
A C4-C5 disc problem may be described on MRI as:
- Disc bulge, meaning the disc extends more broadly beyond its normal edge
- Protrusion, meaning a more focused area of disc sticks out
- Extrusion, meaning disc material has pushed out more than a simple protrusion
- Disc osteophyte complex, meaning disc bulging plus bone spurs
- Uncovertebral spurring, meaning bone spurs near small side joints in the neck
An osteophyte is a bone spur. A bone spur is extra bone that can form with arthritis or wear-and-tear change. These hard bone changes can narrow nerve spaces over time.
Some C4-C5 herniations are “soft,” meaning the main issue is disc material. Others are more arthritis-related, with disc bulging and bone spurs together.
In my practice, the first thing I want to know is not just whether there is a herniation, but whether it is touching the spinal cord or the exiting C5 nerve root.
For a broader overview, see Cervical Disc Herniation: What It Is, How It’s Diagnosed, How It’s Treated.
C4-C5 Disc Bulge vs Herniation
A C4-C5 disc bulge often means the disc has a wider, more general outward shape. A C4-C5 disc herniation often means a more focused area sticks out.
Radiology wording can vary. One MRI report may say “bulge.” Another may say “protrusion” or “herniation” for a similar-looking finding.
The label matters less than:
- Where the disc is pushing
- How much narrowing it causes
- Whether it touches the spinal cord
- Whether it narrows the C5 nerve opening
- Whether the MRI matches your symptoms and exam
Central Canal vs Foraminal Narrowing at C4-C5
There are two main spaces to understand.
Central canal narrowing means the main spinal canal is narrowed. This matters most when there is pressure on the spinal cord.
Foraminal narrowing, also called foraminal stenosis, means the side opening for the nerve is narrowed. Stenosis means narrowing. At C4-C5, foraminal stenosis may affect the C5 nerve root.
A report may say:
- Right C4-C5 foraminal stenosis
- Left C4-C5 foraminal stenosis
- Bilateral C4-C5 foraminal stenosis, meaning both sides are narrowed
A central disc herniation points more toward the spinal cord. A foraminal or lateral herniation points more toward the nerve exit opening.
What Symptoms Can Match C4-C5 or the C5 Nerve Root?
A C4-C5 MRI finding does not automatically explain your symptoms. It matters most when the location and side of the MRI finding match what you feel and what is found on exam.
The C5 nerve root is the nerve that exits at C4-C5. If it is irritated or compressed, it may cause C5 radiculopathy. Radiculopathy means pain, weakness, numbness, or tingling from an irritated spinal nerve root.
Typical C5 nerve root symptoms may include:
- Pain from the neck toward the shoulder
- Pain in the upper outer arm
- Pain around the deltoid area, which is the outer shoulder muscle area
- Weakness lifting the arm away from the body
- Weakness with shoulder abduction, which means raising the arm out to the side
- Sometimes biceps weakness, which can affect elbow bending
- Numbness or tingling, though C5 numbness can be less clear than lower neck nerve patterns
The finding matters most when the side of the MRI finding matches the side of the patient’s pain, weakness, or numbness.
C4-C5 is less classic for symptoms mainly in the hand or fingers. Hand numbness, thumb and index finger symptoms, or middle finger symptoms often point to lower cervical levels or non-spine causes, depending on the pattern.
For comparison, symptoms from the C5-C6 cervical segment and the C6-C7 cervical segment more often involve patterns that travel farther down the arm or into the hand.
What If the MRI Says C4-C5 Spinal Canal Stenosis?
C4-C5 spinal canal stenosis means the main canal around the spinal cord is narrowed at this level.
Mild canal narrowing is common. It may not cause symptoms. More significant narrowing can press on the spinal cord.
When the spinal cord is compressed, the main concern is not just neck pain. The concern is cervical myelopathy. Cervical myelopathy means spinal cord dysfunction in the neck.
You can read more in Cervical Spinal Stenosis & Cervical Myelopathy.
Symptoms That May Suggest Cervical Myelopathy
Symptoms that may suggest cervical myelopathy include:
- Trouble with balance or walking
- Hand clumsiness
- Dropping objects
- Trouble with buttons, handwriting, or fine motor tasks
- New weakness in the arms or legs
- Numbness or tingling in both hands
- Electric-shock sensations down the spine with neck movement
- Bowel or bladder control changes, especially if new
These symptoms do not prove myelopathy, but they are important enough to discuss promptly with a clinician.
If your MRI mentions cord flattening, it means the shape of the spinal cord is indented. If it mentions cord signal change, it means the spinal cord shows an abnormal signal on MRI. Cord signal change is more concerning than mild wear-and-tear change alone and should be reviewed carefully.
Why C4-C5 MRI Findings May or May Not Be the Pain Source
Neck MRIs often show changes at more than one level. This is common, especially with age.
A C4-C5 disc bulge or herniation can be real but not be the main cause of today’s symptoms. The most dramatic phrase in the report is not always the pain source.
A C4-C5 finding must be interpreted with:
- Your symptom location
- How long symptoms have been present
- Your neurologic exam
- The severity of compression
- Whether the spinal cord is involved
- Whether the C5 nerve root is involved
- Whether other levels also show problems
A neurologic exam is a physical exam that checks nerve function. It may include strength, reflexes, feeling, coordination, and walking.
In my practice, I do not treat an MRI report — I treat the patient whose symptoms and exam either do or do not match the MRI finding.
I often remind patients that an MRI can show age-related changes that are real, but not necessarily the cause of today’s symptoms.
Common MRI Phrases at C4-C5 and What They Usually Mean
What I look for on MRI is the location of the narrowing, the severity, and whether the spinal cord or nerve root has enough room.
| MRI phrase | Plain-language meaning | Why it matters |
|---|---|---|
| C4-C5 disc bulge | The disc extends slightly beyond its normal border | May be incidental unless it narrows the canal or foramen |
| C4-C5 disc herniation | A more focal area of disc material sticks out | Matters if it contacts the cord or C5 nerve root |
| Foraminal stenosis | The side opening for the nerve is narrowed | Can irritate or compress the C5 nerve root |
| Central canal stenosis | The main spinal canal is narrowed | Matters most if the spinal cord is compressed |
| Disc osteophyte complex | Disc bulging plus bone spur formation | Often degenerative or arthritis-related |
| Cord flattening | The spinal cord contour is indented | Requires clinical correlation and attention to myelopathy symptoms |
| Cord signal change | The cord shows abnormal signal on MRI | More concerning and should be reviewed carefully with a clinician |
How C4-C5 Problems Are Usually Evaluated
C4-C5 problems are usually evaluated by putting several pieces together.
These may include:
- Your medical history
- Your exact symptom pattern
- A neurologic exam
- MRI review
- Sometimes X-rays
- Sometimes CT, which is a detailed bone scan using X-rays
- Sometimes electrodiagnostic testing
Electrodiagnostic testing means nerve and muscle tests, often called EMG and nerve conduction studies. EMG stands for electromyography. It checks how muscles respond to nerve signals.
The neurologic exam often checks:
- Strength
- Reflexes
- Sensation, meaning feeling in the skin
- Balance and walking
- Signs of spinal cord involvement
The goal is not just to name the MRI finding. The goal is to decide whether the finding fits the symptoms and exam.
Treatment Options Often Considered for C4-C5 Disc Problems
Treatment decisions should come from the combination of symptoms, examination, imaging, and how the problem is affecting daily life — not from one phrase in the MRI report.
Options often considered include:
- Observation when symptoms are mild and there are no concerning neurologic findings
- Physical therapy
- Anti-inflammatory medication when appropriate and prescribed by a clinician
- Nerve pain medication when appropriate and prescribed by a clinician
- Activity modification
- Injections in selected cases
An injection is a procedure that places medication near an irritated nerve or painful spine area. It is not the right choice for every person.
Surgical evaluation may be considered when there is:
- Progressive weakness
- Significant nerve compression with persistent symptoms
- Spinal cord compression or cervical myelopathy
- Persistent disabling arm pain with imaging that matches the symptoms
- Failure of appropriate non-surgical care
Common surgery categories include:
- Anterior cervical discectomy and fusion, or ACDF, which removes the disc from the front of the neck and fuses the bones together
- Cervical disc replacement, which removes the disc and places an artificial disc in selected patients
- Posterior decompression or foraminotomy, which removes pressure from the back of the neck, often near the nerve opening in selected foraminal cases
These are categories, not recommendations for you. The approach depends on the location of compression, spinal alignment, number of levels, arthritis, and other patient-specific factors.
When to Seek Urgent Medical Attention
Seek urgent medical care if you have new or worsening arm or leg weakness, trouble walking or maintaining balance, new hand clumsiness, loss of bowel or bladder control, numbness in the groin/saddle area, fever with severe neck pain, major trauma, or rapidly worsening neurologic symptoms. SpineClarity’s written MRI/case review is not emergency care.
If your MRI mentions severe spinal cord compression, cord signal change, or myelomalacia, discuss it promptly with a qualified clinician.
Myelomalacia means a change in the spinal cord that can suggest cord injury or long-standing compression. It should not be ignored.
When a Written MRI/Case Review Can Help
If your MRI report mentions a C4-C5 disc herniation, foraminal stenosis, spinal canal stenosis, or cord compression and you are not sure what it means, SpineClarity can help you understand the report in context.
A board-certified spine surgeon reviews your symptoms, MRI report, and relevant records. You receive a plain-language written interpretation with a suggested next-step category.
This is not emergency care and does not replace an in-person physician relationship.
FAQ
Is a C4-C5 disc herniation serious?
It depends.
A C4-C5 disc herniation is more important when it compresses the spinal cord or the C5 nerve root. Severity also matters. So does whether your symptoms and exam match the MRI finding.
A small C4-C5 disc bulge with no nerve or cord compression may be less concerning than a large herniation with cord compression or cord signal change.
What nerve comes out at C4-C5?
The C5 nerve root exits at the C4-C5 level.
This nerve can affect the shoulder and upper arm area. It may also affect strength in muscles used to lift the arm away from the body.
What are typical C5 nerve root symptoms?
Typical C5 nerve root symptoms may include neck-to-shoulder pain, upper outer arm pain, and pain around the deltoid region.
Weakness may involve the deltoid muscle. This can make it harder to lift the arm out to the side. Sometimes the biceps can be involved.
Symptoms vary. The MRI still needs to match the symptom pattern and exam.
Can C4-C5 cause hand numbness?
C4-C5 is less classic for isolated hand or finger numbness than lower neck levels.
Hand symptoms may come from lower cervical nerve roots, such as those often affected at C5-C6 or C6-C7. They may also come from non-spine causes, such as nerve compression at the wrist or elbow.
This pattern is not perfect, but it is an important clue.
What does C4-C5 foraminal stenosis mean?
C4-C5 foraminal stenosis means the side opening where the C5 nerve root exits is narrowed.
It matters most if the narrowing compresses or irritates the C5 nerve root and matches your symptoms. The side matters too. Right-sided narrowing should fit right-sided symptoms more than left-sided symptoms, and vice versa.
What does C4-C5 central canal stenosis mean?
C4-C5 central canal stenosis means the main canal around the spinal cord is narrowed at C4-C5.
Mild narrowing may not cause symptoms. More severe narrowing can press on the spinal cord. When the spinal cord is involved, clinicians look carefully for signs of cervical myelopathy.
Do I need surgery for a C4-C5 disc herniation?
Not always.
Many cases start with non-surgical care when there is no progressive neurologic deficit or cervical myelopathy. A neurologic deficit means loss of nerve function, such as weakness, reflex change, or sensory loss.
Surgery may be considered when there is worsening weakness, spinal cord compression with myelopathy, or persistent disabling symptoms that match the MRI.
Can a C4-C5 finding be incidental?
Yes.
An incidental finding is something seen on MRI that may not be causing symptoms. Cervical disc bulges, degeneration, and stenosis can appear in people without neck or arm symptoms, especially with age.
That does not mean the finding is fake. It means the MRI must be matched to your symptoms, exam, and the degree of nerve or spinal cord compression.
References
Boden, S. D., McCowin, P. R., Davis, D. O., Dina, T. S., Mark, A. S., & Wiesel, S. (1990). Abnormal magnetic-resonance scans of the cervical spine in asymptomatic subjects. Journal of Bone and Joint Surgery. American Volume, 72(8), 1178–1184.
Bono, C. M., Ghiselli, G., Gilbert, T. J., Kreiner, D. S., Reitman, C., Summers, J. T., et al. (2011). An evidence-based clinical guideline for the diagnosis and treatment of cervical radiculopathy from degenerative disorders. The Spine Journal, 11(1), 64–72. https://doi.org/10.1016/j.spinee.2010.10.023
Davies, B. M., Mowforth, O. D., Smith, E. K., & Kotter, M. R. N. (2018). Degenerative cervical myelopathy. BMJ, 360, k186. https://doi.org/10.1136/bmj.k186
Fardon, D. F., Williams, A. L., Dohring, E. J., Murtagh, F. R., Gabriel Rothman, S. L., & Sze, G. K. (2014). Lumbar disc nomenclature: version 2.0. The Spine Journal, 14(11), 2525–2545. https://doi.org/10.1016/j.spinee.2014.04.022
Fehlings, M. G., Tetreault, L. A., Riew, K. D., Middleton, J. W., Wang, J. C., Ahn, H., et al. (2017). A clinical practice guideline for the management of patients with degenerative cervical myelopathy. Global Spine Journal, 7(3 Suppl), 70S–83S. https://doi.org/10.1177/2192568217701914
Iyer, S., & Kim, H. J. (2016). Cervical radiculopathy. Current Reviews in Musculoskeletal Medicine, 9(3), 272–280. https://doi.org/10.1007/s12178-016-9349-4
Kelly, J. C., Groarke, P. J., Butler, J. S., Poynton, A. R., & O’Byrne, J. M. (2012). The natural history and clinical syndromes of degenerative cervical spondylosis. Advances in Orthopedics, 2012, 393642. https://doi.org/10.1155/2012/393642
Magnus, W., Viswanath, O., Viswanathan, V. K., & Mesfin, F. B. Cervical Radiculopathy. In: StatPearls. Treasure Island, FL: StatPearls Publishing. Available via NCBI Bookshelf.
Matsumoto, M., Fujimura, Y., Suzuki, N., Nishi, Y., Nakamura, M., Yabe, Y., & Shiga, Y. (1998). MRI of cervical intervertebral discs in asymptomatic subjects. Journal of Bone and Joint Surgery. British Volume, 80-B(1), 19–24.
McDonald, M. A., Kirsch, C. F. E., Amin, B. Y., Aulino, J. M., Bell, A. M., Cassidy, R. C., et al. (2019). ACR Appropriateness Criteria® Cervical Neck Pain or Cervical Radiculopathy. Journal of the American College of Radiology, 16(5S), S57–S76. https://doi.org/10.1016/j.jacr.2019.02.023
Nakashima, H., Yukawa, Y., Suda, K., Yamagata, M., Ueta, T., & Kato, F. (2015). Abnormal findings on magnetic resonance images of the cervical spines in 1211 asymptomatic subjects. Spine, 40(6), 392–398. https://doi.org/10.1097/BRS.0000000000000775
Nouri, A., Martin, A. R., Kato, S., Reihani-Kermani, H., Riehm, L., & Fehlings, M. G. (2017). The relationship between MRI signal intensity changes and clinical presentation in degenerative cervical myelopathy. Spine, 42(24), 1851–1858. https://doi.org/10.1097/BRS.0000000000002297
Nouri, A., Tetreault, L., Singh, A., Karadimas, S. K., & Fehlings, M. G. (2015). Degenerative cervical myelopathy: Epidemiology, genetics, and pathogenesis. Spine, 40(12), E675–E693. https://doi.org/10.1097/BRS.0000000000000913