What Causes Sciatica in the First Place?

Sciatica is caused by compression or irritation of the sciatic nerve, the longest nerve in the body, which runs from the lower back through the hips and down each leg. Most cases trace back to a structural problem in the lumbar spine, such as a herniated disc, bone spur, or spinal misalignment, that places direct pressure on the nerve root.

In this blog post, we’ll cover everything you need to know about what causes sciatica and how you can treat sciatica if you do have it.

Understanding the Sciatic Nerve

The sciatic nerve originates from nerve roots in the lower lumbar and sacral spine, specifically at levels L4, L5, S1, S2, and S3. These roots bundle together and travel through the buttocks and down the back of each leg, all the way to the foot.

Because this nerve is so large and covers so much territory, any irritation at the source in the spine can produce symptoms that radiate far from where the actual problem exists. That is why so many people with sciatica feel pain in their calf or foot without realizing the true issue begins in their lower back.

The Most Common Causes of Sciatica

Sciatica is a symptom, not a diagnosis on its own. Sciatica is the result of something compressing or inflaming the sciatic nerve.

Based on our expertise and our experience working with sciatica clients in San Diego, here are the most frequently identified sciatica causes we see:

Herniated or Bulging Discs

The discs between your spinal vertebrae act as shock absorbers. When the soft inner material of a disc pushes outward through a crack in the outer layer, it can press directly on a nearby nerve root. Herniated or bulging discs are the single most common cause of sciatica, and it often happens gradually from repetitive stress, poor posture, or a sudden awkward movement.

Spinal Stenosis

Spinal stenosis refers to a narrowing of the spinal canal. As this canal becomes more restricted, the nerve roots traveling through it can become compressed. This condition is more common in adults over 50 and often develops slowly over time due to arthritis or degenerative changes in the spine.

Vertebral Misalignment

When one or more of the vertebrae in the lower spine shift out of their proper position, they can encroach on the space the nerve roots need to exit the spine freely. Even subtle misalignments, particularly in the upper cervical spine, can alter the mechanics of the entire spinal column and contribute to nerve stress lower down. This is an area we pay close attention to at our practice, because correcting the underlying structural problem often produces significant relief for patients dealing with sciatic pain.

Piriformis Syndrome

The piriformis is a small muscle located deep in the buttock. In some people, the sciatic nerve runs directly through this muscle rather than beneath it. When the piriformis becomes tight, inflamed, or goes into spasm, it can compress the sciatic nerve and mimic the symptoms of disc-related sciatica. This is sometimes called “false sciatica” because the problem originates in the muscle, not the spine itself.

Degenerative Disc Disease

Over time, spinal discs lose height and hydration. As they thin out, the space between vertebrae decreases, which can put pressure on nearby nerve roots. This type of degeneration is a normal part of aging, but it accelerates significantly when the spine is misaligned or subjected to chronic poor posture.

Spondylolisthesis

This condition occurs when one vertebra slips forward over the one below it. The displaced vertebra can narrow the opening through which the nerve exits and compress the sciatic nerve root. It can be caused by a stress fracture, degenerative changes, or even a congenital defect present from birth.

If you are suffering from one of the above issues and are located in San Diego, California, consider reaching out to us for help. You can see many of the main issues we treat here.

“I have had multiple injuries over the years and can always count on Intouch Chiropractic to help me heal! Both doctors do amazing work and they always have the latest technology. Their advanced laser therapy is incredible. I feel better already after only 2 visits.” – Intouch Chiropractic Review by Elsa G.

Common Symptoms of Sciatica

Knowing what sciatica feels like helps you recognize it early and seek care before it worsens. Symptoms vary from person to person but typically include:

• Sharp, shooting, or burning pain that travels from the lower back through the buttock and down one leg
• Numbness or tingling in the leg, calf, or foot
• Muscle weakness in the affected leg
• Pain that worsens when sitting, standing for long periods, or sneezing
• A constant ache on one side of the lower back or buttock

Sciatica almost always affects only one side of the body at a time. If you are experiencing symptoms on both sides simultaneously, it is important to seek evaluation promptly, as this can indicate a more serious condition.

Risk Factors That Increase Your Likelihood of Sciatica

Some people are more prone to developing sciatica than others. Common risk factors include:

• Age: Spinal degeneration becomes more common after age 40.
• Sedentary lifestyle: Sitting for long hours increases disc pressure and weakens the core muscles that support the spine.
• Physically demanding work: Jobs that require heavy lifting, twisting, or prolonged driving are associated with higher sciatica rates.
• Obesity: Excess body weight increases the mechanical load on the lumbar spine.
• Diabetes: Elevated blood sugar can damage nerves, making them more susceptible to compression injuries.
• Previous spinal injury: A history of trauma to the lower back raises the risk of structural changes that compress the sciatic nerve.

When to See a Doctor for Sciatica

Many people try to wait out sciatic pain, hoping it resolves on its own. While mild cases sometimes improve with rest, there are situations where prompt evaluation is important:

• Pain that is severe or rapidly worsening
• Symptoms that have persisted for more than four to six weeks without improvement
• Loss of bladder or bowel control (this requires emergency care)
• Progressive muscle weakness in the leg
• Pain following a significant injury or accident

Waiting too long to address the root cause of sciatica can allow the underlying structural problem to worsen. Early intervention typically leads to faster recovery and better long-term outcomes.

How Chiropractic Care Addresses the Root Cause

Most conventional approaches to sciatica focus on managing pain rather than correcting what is causing the nerve compression in the first place.

At Intouch Chiropractic in Mission Valley, we take a different approach. Our focus is on identifying and correcting the specific spinal misalignments that are contributing to nerve irritation. By restoring proper alignment and joint movement, we reduce the pressure on the sciatic nerve without relying on medication or surgery.

For patients whose sciatica stems from disc involvement, we may also incorporate spinal decompression therapy, which gently creates space between the vertebrae to allow the disc to retract away from the affected nerve. This combination of precise chiropractic correction and decompression is one of the most effective conservative approaches available for true sciatic nerve compression.

Learn more about the benefits of spinal decompression at our blog.

If you have been dealing with lower back pain, hip pain, or shooting leg pain and suspect sciatica may be the cause, the best next step is a thorough evaluation.

Our team at Intouch Chiropractic in San Diego serves patients throughout the area and is experienced in identifying the exact structural factors driving sciatic symptoms. Contact us today to schedule a consultation and find out if chiropractic care is right for you.

Frequently Asked Questions About How Sciatica is Caused

Can sciatica go away on its own?

Mild sciatica can sometimes improve with rest and gentle movement over several weeks. However, if the underlying cause, such as a herniated disc or spinal misalignment, is not addressed, symptoms often return or worsen over time.

Is sciatica always caused by a disc problem?

No. While herniated discs are the most common cause, sciatica can also result from spinal stenosis, vertebral misalignment, piriformis syndrome, or degenerative changes in the lumbar spine. A proper evaluation is needed to identify the specific cause.

How do I know if my back pain is actually sciatica?

True sciatica typically involves pain, numbness, or tingling that radiates from the lower back into the buttock and down one leg. If your pain stays primarily in the low back without traveling down the leg, it may be a different condition altogether.

Can posture really cause sciatica?

Poor posture over time can contribute to spinal misalignment and disc degeneration, both of which are established causes of sciatic nerve compression. Chronic forward head posture, for example, alters the mechanics of the entire spine, including the lumbar region.

Does chiropractic care actually help sciatica?

For many patients, yes. When sciatica is caused by a structural issue in the spine, chiropractic adjustments that restore proper alignment can reduce nerve compression and provide significant relief. Results depend on the specific cause and how long the condition has been present.