Disc Bulge. Slipped Disc. Herniated Disc. What's The Difference?!
Oct 16, 2025In this blog piece, we will be discussing the following:
- The Human Spine
- What's the difference between a disc bulge, slipped disc and herniated disc?
- What causes herniated discs?
- What are the signs and symptoms of a herniated disc?
- How is a herniated disc diagnosed?
- What are the treatment options for a herniated disc?
- The Final Word on Herniated Discs
To understand the above terms, we must first have a basic knowledge of the spinal column, its parts and functions:
The Human Spine
There are 33 separate interlocking bones in our spine, each one called vertebra, and collectively called vertebrae. There are 7 vertebrae in the cervical spine, 12 in the thoracic spine, 5 in the lumbar spine, 5 in the sacral region and 4 in the coccygeal region. Only the top 24 vertebrae are moveable, with the remainder being fused. The vertebrae are the building blocks of the spine and make up the spinal column.
In the lumbar region, there are 5 large vertebrae (named L1-5). The main function of the lumbar vertebrae is to bear the weight of the entire trunk whilst providing a moveable support structure and to protect the spinal cord.
Located between each of the vertebrae are the intervertebral discs. A healthy intervertebral disc is made up of two parts: the nucleus pulposus (a gelatinous-like centre) and the annulus fibrosus (a tough outer ring rich in pain-carrying nerve fibres). The discs act as shock absorbers. When a disc loses its elasticity, it may protrude beyond its boundary and compress spinal nerves. The most common herniation occurs between L4 and L5, where movement and weight-bearing are greatest.
As the architectural centre of the body, the spine is also affected by lower limb biomechanics—meaning dysfunction or injury in the legs can predispose the spine to injury or weakness.
What’s the difference between a disc bulge, slipped disc and herniated disc?
These terms are often used interchangeably to describe disc protrusion beyond its normal boundary. Technically, a herniated disc occurs when the annulus cracks or ruptures, allowing the nucleus pulposus to push out—sometimes called a ruptured or prolapsed disc. A disc bulge refers to a general enlargement where the annulus remains intact and may not compress spinal nerves.
For simplicity, this article uses “disc herniation” to encompass all of these terms.
What causes herniated discs?
Causes include poor lifting technique, repetitive bending/twisting, and physical wear from work or sports. Ageing, obesity, and smoking also increase risk as discs lose water content and flexibility. Most herniations result from cumulative strain rather than a single incident.
What are the signs and symptoms of a herniated disc?
The size of the herniation doesn’t always correlate with pain. Some large bulges are asymptomatic, while smaller ones can cause severe discomfort. Symptoms vary depending on nerve involvement: pain radiating from the lower back to the leg, tingling, numbness, muscle weakness, or even foot drop. Pain worsens with sitting, bending, or lifting and often eases when lying down with knees bent.
Severe cases may involve Cauda Equina Syndrome (emergency), causing incontinence and numbness in the “saddle area.” Piriformis Syndrome can also mimic disc pain due to sciatic nerve compression.
How is a herniated disc diagnosed?
Diagnosis begins with a detailed history and physical exam assessing strength, reflexes, and sensation. MRI is the most accurate imaging tool, but findings must be correlated clinically since even young adults can show disc degeneration. X-rays can reveal disc height loss or bone changes but not herniations directly.
What are the treatment options for a herniated disc?
Treatment can be conservative or surgical.
Conservative Options:
- Self-care: Most resolve within 6 weeks to 4 months. Rest briefly, then resume gentle activity. Ice reduces inflammation; heat eases spasms.
- Medication: NSAIDs and corticosteroids reduce inflammation; narcotics may be used short-term under medical guidance.
- Manual Therapy: Osteopathy or physiotherapy restores mobility, corrects muscle imbalances, strengthens the spine, and prevents recurrence.
Surgical Options: Surgery (e.g., discectomy) is a last resort if conservative care fails. It removes part of the nucleus pulposus and has an ~85% success rate.
The Final Word on Herniated Discs
Pain is your body’s warning signal—don’t ignore it. Push yourself, but within reason. Train, rest, and recover properly. Dysfunction in one area affects the whole body—think of ripples in a pond.
Protect your spine by strengthening core stability, avoiding repetitive strain, lifting correctly, staying hydrated, and maintaining regular manual therapy like Osteopathy or Massage.
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