Understanding Sciatica: Why Does My Leg Hurt?

A sharp, electric sensation shoots down your buttock, along the back of the thigh, and sometimes all the way to the big toe. Your leg looks completely normal. But the pain is very real, and it can be severe enough to disrupt sleep, work, and walking.

This pattern is called sciatica. It is important to understand that sciatica is not a disease in itself — it is a symptom, almost always caused by a problem back in the lower spine, not the leg.

The Sciatic Nerve: Why Leg Pain Starts in the Back

The sciatic nerve is the longest and thickest nerve in the body. It forms from several nerve roots exiting the lower spine, travels through the buttock, and runs the entire length of the leg down to the foot.

Because of this long path, irritation or compression at the root of the nerve — up in the spine — can cause pain, numbness, or weakness anywhere along its route. This is why sciatica is frequently mistaken for a hip or leg problem when the actual source is a lower back issue.

Common Causes of Sciatica

1. Herniated Disc (Most Common Cause)

When the soft inner material of a spinal disc bulges or leaks out, it can directly press on a nearby nerve root. This is the most frequent cause of sciatica, and the treatment ladder for it is covered in detail in our guide to slip disc treatment options.

2. Spinal Stenosis

As the spine ages, the canal that houses the nerves can narrow due to bone spurs and thickened ligaments, gradually compressing the nerve roots. This often causes leg pain that worsens specifically with walking or standing and eases with sitting or leaning forward — a pattern called neurogenic claudication.

3. Piriformis Syndrome

The piriformis, a small muscle deep in the buttock, can tighten and irritate the sciatic nerve as it passes nearby. This is sometimes called "false sciatica" because the spine itself may be entirely normal — the problem is muscular, not a disc or nerve root.

4. Spondylolisthesis

This occurs when one vertebra slips forward relative to the one below it, which can stretch or pinch the nerve roots as they exit the spine.

Recognising the Symptoms

Sciatica has a fairly distinctive pattern worth knowing:

Pain typically affects one side — buttock, back of thigh, calf, or foot
Sensations range from burning and tingling to sharp, shooting pain or numbness
Pain often worsens with sitting, coughing, or sneezing, which increases pressure on the nerve
Weakness in the foot, such as difficulty lifting the toes, is a more serious sign and shouldn't be ignored

If pain is accompanied by loss of bladder or bowel control, or rapidly worsening weakness in both legs, this needs emergency evaluation — details are covered in when back surgery is needed.

How Sciatica Is Treated

Treatment targets the underlying spinal cause, not just the leg symptom:

Nerve gliding exercises: Specific stretches that gently mobilise the irritated nerve through its natural range of motion
Posture correction: Reducing prolonged slouched sitting, which increases pressure on lower spinal discs
Medication: Nerve-specific pain medication often works better for sciatica than standard painkillers, since the pain originates from nerve irritation rather than simple inflammation
Physiotherapy: A structured program addressing both the acute pain and the underlying mechanical cause
Joint injections: For persistent cases, an epidural steroid injection can reduce inflammation around the nerve root directly

For a broader view of how sciatica fits into overall back pain management, see our guide to lower back pain treatment. When conservative measures don't resolve symptoms, minimally invasive spine surgery can address the underlying nerve compression directly.

FAQs

How long does sciatica usually last? Many episodes improve within a few weeks with appropriate conservative treatment, though this varies significantly depending on the underlying cause and severity. Persistent or worsening symptoms beyond several weeks warrant a proper evaluation rather than continuing to wait it out.

Is sciatica the same as a slipped disc? Not exactly — sciatica is the pattern of leg pain, and a herniated (slipped) disc is one common cause of it, though not the only one. Spinal stenosis, piriformis syndrome, and spondylolisthesis can all produce a similar sciatica pattern.

Should I rest or stay active with sciatica? Gentle, guided movement is generally more helpful than prolonged bed rest, which can stiffen the back and slow recovery. That said, activities that clearly worsen the shooting pain should be modified until you've been properly assessed.

Can sciatica come back after it resolves? Yes, particularly if the underlying cause (such as a disc that continues to bulge under strain, or poor core strength) isn't addressed. This is why physiotherapy focused on long-term strength and posture is valuable even after acute pain settles.

Takeaway

Don't just treat the leg pain — treat the spine causing it. Identifying the exact source of nerve irritation, usually confirmed with a clinical exam and MRI if needed, is the key to fixing sciatica rather than just masking the symptom.

If leg pain is affecting your daily life, book a spine evaluation with Dr. Abhijit Kale to pinpoint the cause and start the right treatment.