That burning, shooting pain that starts in your lower back and travels down your buttock, through the back of your thigh, and sometimes all the way to your foot has a name: sciatica. It's not a diagnosis exactly — it's a symptom. The question is what's causing the sciatic nerve to fire when it shouldn't.
What the sciatic nerve is
The sciatic nerve is the longest nerve in your body, running from the lower spine all the way to the foot. It forms from several nerve roots (L4 through S3) that merge in the pelvis before traveling down each leg.
When something presses on those nerve roots or on the nerve itself, you get the classic pattern: radiating pain that follows the nerve's path, often with numbness or tingling in the leg or foot, sometimes with weakness.
Where the symptoms land often points to which nerve root is involved. Pain shooting down the back of the thigh and calf into the heel suggests L5 or S1. Pain toward the big toe more likely involves L4 or L5. Your doctor uses these patterns, along with your exam and imaging, to narrow it down.
The most common causes
Herniated disc accounts for the majority of sciatica cases. The discs between your vertebrae have a tough outer shell and a softer inner core. When the shell tears or weakens, the inner material can press on a nearby nerve root. This happens most often at L4-L5 or L5-S1.
Disc herniations frequently occur from nothing dramatic — a sneeze, bending over to pick something up, getting out of a car. The disc was already under stress. The small incident just happened to be the one that pushed it over.
Spinal stenosis is a narrowing of the spinal canal or the openings where nerve roots exit. It's degenerative, developing over years. Unlike disc herniation (which tends to cause sharp pain that eases with rest), stenosis classically causes leg pain when walking that improves when you sit down or lean forward. It's more common after 60.
Piriformis syndrome is worth knowing about. The piriformis muscle sits in the buttock, and in some people the sciatic nerve runs through or underneath it. When this muscle is tight or irritated, it can compress the nerve. The distinguishing feature: buttock pain without lower back involvement, made worse by sitting and hip rotation. It's often misdiagnosed as lumbar sciatica when the real problem is muscular.
Spondylolisthesis is when one vertebra slips forward over the one below it, narrowing the space for nerve roots. It can be degenerative or come from a stress fracture in the vertebra. Common on imaging in middle-aged adults, though not always the pain source.
What the research says about recovery
Here's something most patients aren't told upfront: the majority of sciatica from a disc herniation improves on its own. Studies consistently show 80 to 90% of patients recover within 6 to 12 weeks without surgery.
The disc material pressing on the nerve is treated as a foreign body by the immune system. Over weeks to months, it gets attacked, shrinks, and the nerve settles down. This happens whether you have surgery or not.
The practical takeaway: for new-onset sciatica from a herniated disc, the right first move is conservative treatment and patience, not an immediate MRI and a surgical referral.
Managing the acute phase
The first two weeks are often the worst. A few things that actually help:
Movement, not bed rest. Staying horizontal makes sciatica worse in most cases. Short walks, moving around the house — anything that keeps you active is better than lying still. Complete rest beyond 48 hours consistently shows worse outcomes in the research.
Position of comfort. Most people feel better lying on their side with a pillow between their knees, or on their back with knees bent and supported. Positions that load the disc — sitting, bending forward — tend to aggravate symptoms. Standing and walking are usually more tolerable than sitting.
NSAIDs. Ibuprofen or naproxen help with both pain and nerve inflammation. Take them with food, use the lowest effective dose, and avoid them for more than 10 consecutive days without checking with a doctor.
Ice, then heat. Ice in the first 48 to 72 hours when the area is acutely inflamed. After that, heat tends to feel better and helps with surrounding muscle spasm.
When to see a doctor immediately
Most sciatica can wait for a non-urgent clinic appointment. These situations cannot:
- Numbness or weakness in both legs simultaneously
- Loss of bladder or bowel control, or numbness in the inner thighs and groin (this is called cauda equina syndrome and is a surgical emergency)
- Rapidly worsening leg weakness over hours to days
- Sciatica that started after a fall or accident
Cauda equina syndrome is the one true emergency in spine care. If you have sciatica plus new difficulty urinating or any loss of bowel control, go to the emergency room — not urgent care, not a clinic visit scheduled for next week. The ER, immediately. Delay risks permanent paralysis.
Physical therapy
For most people, PT is the most effective treatment for sciatica outside of simply waiting it out. The goal is reducing nerve tension, building the muscles that support the lumbar spine, and teaching you movements that don't load the disc.
What good PT for sciatica actually involves:
Neural flossing (nerve mobilization). Specific movements that help the sciatic nerve glide freely through the surrounding tissue rather than being stuck against it. They feel uncomfortable at first and most people notice real improvement within two weeks.
Extension-based exercises for disc herniations. McKenzie press-ups — essentially pushing yourself up from a prone position — help centralize pain in many people with disc herniations. The radiating leg pain diminishes as the disc material shifts away from the nerve root. If your PT only has you doing flexion exercises for a herniated disc, question it.
Glute and core strengthening. Strong surrounding muscles reduce how much load the disc has to absorb. Glute bridges, dead bugs, and bird-dogs are the unglamorous staples of lumbar rehab. They work.
Epidural steroid injections
When pain is severe enough to prevent sleep or any normal functioning, an epidural steroid injection can provide meaningful relief for two to four weeks — enough of a window to begin physical therapy.
ESIs reduce inflammation around the nerve root temporarily. The research shows they work well for short-term pain control but don't change long-term outcomes compared to no injection. They're a management tool to make the recovery window tolerable, not a fix.
When surgery is the right call
Surgery for lumbar disc herniation — when indicated correctly — is one of the most reliably effective procedures in orthopaedic surgery.
The right indication: significant leg pain that hasn't improved after 6 to 12 weeks of proper conservative treatment, imaging showing a herniation that matches your clinical symptoms, and you want to speed up recovery rather than wait further.
The wrong indication: back pain without significant leg symptoms, a disc bulge on MRI that doesn't match your exam findings, or surgery as a first step before trying anything else.
The standard procedure is a microdiscectomy: a small incision, removal of the disc fragment pressing on the nerve, same-day discharge. Most people notice immediate improvement in leg pain. Back pain takes longer.
One honest caveat: surgery doesn't prevent future herniations. The disc remains vulnerable. Lifestyle factors — carrying excess weight, smoking, prolonged sitting — influence recurrence more than what happens in the operating room.
