Key Takeaway: Sciatica is pain that travels along the path of the sciatic nerve, from the lower back through the buttock and down one leg. It is caused by compression or irritation of the sciatic nerve roots, most commonly from a herniated disc or spinal stenosis. Most cases resolve with non-surgical treatment, including spinal decompression therapy and targeted rehabilitation.
Sciatica is one of the most searched pain conditions in Canada, and for good reason. The combination of lower back pain, searing buttock pain, and leg pain that seems to follow a specific path is distinctive, often debilitating, and frequently misunderstood. Many people assume it’s a diagnosis in itself. It is actually a symptom, one that can have several different structural causes, each of which responds somewhat differently to treatment.
This guide explains what sciatica pain actually is, what causes it, what the warning signs are, and when you should see a specialist.
What Is Sciatica?
Sciatica refers to pain that radiates along the sciatic nerve, the largest and longest nerve in the human body. The sciatic nerve is formed by several nerve roots (L4, L5, S1, S2, and S3) that exit the lower lumbar and sacral spine, combine in the pelvis, and then travel down the back of each leg to the foot.
When one or more of these nerve roots is compressed or irritated where it exits the spine, the result is pain, numbness, or other symptoms that radiate along the nerve’s pathway. This is what most people experience as sciatica.
It is important to note that sciatica is a symptom pattern, not a diagnosis. What you need to know is what is compressing the nerve — because that is what determines the most effective treatment.
[suggest: anatomical illustration of the sciatic nerve pathway from lumbar spine through buttock and down the leg]
What Causes Sciatica?
Lumbar Disc Herniation
This is the most common cause of sciatica, particularly in people under 50. When a disc in the lower back herniates, the inner disc material can press directly on one of the nerve roots that forms the sciatic nerve. The L4-L5 and L5-S1 disc levels are responsible for the vast majority of sciatica cases.
Our herniated disc treatment Toronto page explains how disc herniations develop and what non-surgical treatment looks like. Our related guide on what is a bulging vs. herniated disc clarifies the distinction between the two.
Lumbar Spinal Stenosis
In people over 50, spinal stenosis — narrowing of the spinal canal — is a common cause of sciatica-like symptoms. As the canal narrows, the nerve roots passing through it are compressed, producing bilateral or alternating leg pain, particularly with walking or standing. This is called neurogenic claudication. For more on how stenosis is diagnosed and treated, see our non-surgical spinal stenosis treatment article.
Degenerative Disc Disease
As discs wear down and lose height with age, the foramina (openings through which nerve roots exit the spine) can narrow, compressing the nerve. Degenerative disc disease is often an underlying factor in both herniation-related and stenosis-related sciatica. See our degenerative disc disease treatment article for more context.
Piriformis Syndrome
The piriformis muscle sits in the buttock, and the sciatic nerve passes either underneath or through it. When the piriformis is tight, inflamed, or in spasm, it can irritate the sciatic nerve and produce sciatica-like symptoms. This is sometimes called “piriformis syndrome” and is distinct from spinal causes, as the nerve is being irritated in the buttock rather than at the spine.
Other Causes
Less commonly, sciatica can be caused by spinal tumours, infections, fractures, or pregnancy-related changes. These are less frequent but important to rule out in atypical presentations.
What Does Sciatica Pain Feel Like?
The symptoms of sciatica are fairly distinctive, though they vary in intensity and exact location depending on which nerve root is involved.
Most people with sciatica describe some combination of:
- A sharp, burning, or electric shock-like pain starting in the lower back or buttock and travelling down one leg
- A deep aching or throbbing pain in the buttock or back of the thigh
- Numbness or tingling anywhere along the leg, into the calf, ankle, or foot
- Weakness in the leg, foot, or toes
- Pain that is typically worse on one side only
- Symptoms that worsen with sitting for long periods, sneezing, coughing, or bending forward
- Some relief with walking, lying down, or changing positions
Sciatica almost always affects one leg at a time. Bilateral leg symptoms, affecting both legs, are more suggestive of spinal stenosis or a central disc herniation and should be evaluated promptly.
Warning Signs: When Sciatica Requires Urgent Care
Most sciatica is not a medical emergency. However, the following symptoms require same-day or emergency evaluation:
- Sudden loss of bladder or bowel control alongside leg pain or weakness
- Numbness in the inner thighs, groin, or saddle area (called saddle anaesthesia)
- Rapidly worsening leg weakness over hours or days
These can indicate cauda equina syndrome, a serious spinal emergency caused by compression of multiple nerve roots at once. It requires emergency surgical decompression to prevent permanent nerve damage.
Sciatica vs. Other Back and Leg Pain Conditions
Not all leg pain is sciatica. Here is how it compares to some commonly confused conditions:
| Condition | Pain Pattern | Triggered By | Relieved By |
|---|---|---|---|
| Sciatica (disc herniation) | Back → buttock → one leg | Sitting, bending, coughing | Lying down, walking |
| Sciatica (stenosis) | Both legs, heavy or cramping | Walking, standing | Sitting, bending forward |
| Piriformis syndrome | Deep buttock, sometimes into leg | Sitting, direct pressure | Stretching, movement |
| Vascular claudication | Calf cramping | Walking | Standing still |
| Hip arthritis | Groin, inner thigh, knee | Weight bearing | Rest |
If you have leg pain without a clear back component, or pain that doesn’t follow the typical sciatic nerve pathway, a thorough assessment is needed to identify the actual source.
How Is Sciatica Treated?
For the majority of patients, sciatica responds well to non-surgical care. Our sciatica treatment page covers the full treatment approach in detail, including spinal decompression therapy, physiotherapy, and what to expect from a structured program at Back Clinics of Canada. Wondering how long your sciatica will last? See our article on how long sciatica lasts and whether it goes away on its own. For practical day-to-day management, see how to deal with sciatica pain at home.
The cornerstone of treatment at our clinic is the spinal decompression service, which directly addresses the disc herniation or nerve compression causing the sciatica. By reducing intradiscal pressure and drawing herniated material away from the nerve root, decompression can produce significant relief in a structured course of treatment.
Frequently Asked Questions
Q: What is sciatica pain and where do you feel it? A: Sciatica pain is felt along the path of the sciatic nerve, which runs from the lower back through the buttock and down the back of the leg to the foot. It is typically felt on one side and is often described as burning, shooting, or electric in quality.
Q: Is sciatica serious? A: Most cases of sciatica are not serious in the long term and resolve with appropriate non-surgical treatment. However, sciatica with sudden bladder or bowel changes, or rapid worsening weakness, is a medical emergency and requires immediate evaluation.
Q: How do I know if I have sciatica or something else? A: The key feature of sciatica is leg pain that follows the path of the sciatic nerve, typically from the lower back through the buttock and down one leg. Pain limited to the lower back alone, or confined to the hip or groin without leg involvement, is more likely another condition. A clinical assessment with imaging can confirm the diagnosis.
Q: Can sciatica go away on its own? A: Mild sciatica can improve with time and simple measures. However, sciatica caused by a significant disc herniation or stenosis typically requires structured treatment to resolve fully. Waiting months without treatment can allow the underlying nerve compression to persist and cause longer-term nerve irritation.
Q: Who should I see for sciatica in Toronto? A: For sciatica related to disc herniation, stenosis, or degenerative disc disease, a non-surgical spine clinic specializing in spinal decompression is one of the most targeted options. Back Clinics of Canada in Vaughan has treated sciatica non-surgically for over 34 years.
Think You Might Have Sciatica?
Understanding what’s causing your pain is the first step toward treating it effectively. Back Clinics of Canada offers comprehensive sciatica assessment and non-surgical treatment for patients across Toronto and Vaughan.
Call us at 416-633-3666, book your consultation online or visit our clinic today.