Lumbar herniated disc and sciatica
Between 85 and 90 per cent of lumbar herniated discs stop hurting within six to twelve weeks without anyone operating on them, and two out of three resorb on their own. Fewer than one in ten end up in an operating theatre. This page is about how to work out which group you are in.
You have most likely arrived here holding an MRI report that says "disc herniation at L4-L5" or "L5-S1", with pain running down your leg and the word surgery circling in your head. Before going any further, the most important fact on this page: most people in your situation are not operated on, and not because they endure it, but because it goes away.
What it actually is
Between one vertebra and the next there is a disc, which works as a cushion. It has a fibrous ring on the outside and a gel-like core inside. When the ring cracks, part of that core escapes and can press on a nerve root running just alongside.
That is a herniated disc. The leg pain does not come from the disc: it comes from the root, irritated and compressed. That is why the leg hurts and the back does not, and why the pain follows such a precise path — the buttock, the back of the thigh, the calf, sometimes as far as the big toe. That path tells the doctor which root is involved, often before looking at the MRI.
Ninety-five per cent occur at the last two levels of the lumbar spine, L4-L5 and L5-S1, the ones that carry the most load.
How it feels
The pain of a lumbar herniated disc has a recognisable personality. It usually starts in the back and within a few days "moves down" into the leg, and when it does, the back often improves. It gets worse with coughing, with sneezing, with straining on the toilet. It gets worse sitting, above all in low seats and in the car. Many people are better standing or walking than sitting, which is exactly the opposite of what you would expect from a spinal problem.
It may come with pins and needles, with an area of the leg or foot that feels numb, and sometimes with weakness: it is hard to stand on tiptoe, or the foot "catches" when you walk.
The numbers worth knowing
These are the ones that change the conversation:
- Of every hundred people with a symptomatic lumbar herniated disc, between 85 and 90 improve within six to twelve weeks without any major intervention.
- Around two out of three herniated discs treated without surgery resorb. They do not "settle back into place": the body digests them. A 2017 meta-analysis measured a resorption rate of 66.7 per cent. The immune system recognises the herniated material as foreign, new vessels and cells move in and eat it away, and within months it can disappear from the MRI.
- Only between 2 and 10 per cent of all lumbar herniated discs end up being operated on, because conservative treatment has failed.
- In the long run, those who have surgery and those who do not end up in much the same place. Surgery shortens the suffering: people who are operated on improve sooner. But at six or twelve months, and at ten years as well, the two groups arrive somewhere similar. Surgery buys time and quick relief, not a different destination.
And one number worth knowing before drawing conclusions from an MRI. In 2015 a review pooled thirty-three studies with 3,110 people with no back pain at all. Among those aged fifty, 80 per cent had disc degeneration, 60 per cent had a disc bulge and 36 per cent had a protrusion. Healthy people, with no symptoms.
Put another way: the fact that the MRI shows something does not mean that something is the cause of the pain. You treat the patient, not the image.
When not to wait
Almost everything about a lumbar herniated disc can wait a few days. These things cannot. If they appear, go to an emergency department the same day:
- Difficulty passing urine, or difficulty telling that the bladder is full, or involuntary loss of urine or stool.
- Numbness in the area that rests on a bicycle saddle: the groin, the genitals, around the anus.
- Weakness that progresses over hours or a few days: the foot that drops, the leg that gives way.
- Severe pain in both legs at once, coming on abruptly.
Together these are called cauda equina syndrome, and it is one of the few genuine spinal emergencies: the outcome depends on operating quickly. It is rare, which is exactly why it is worth being able to recognise.
What you will hear that is not true
"The disc has slipped out of place and needs putting back." There is no manual manoeuvre that returns the core of the disc inside the ring. When someone improves after a manipulation, they improved because of the natural course of the condition, which is to improve. Resorption is a biological process, not a mechanical one.
"If the MRI shows a herniated disc, it has to be operated on." See above: 36 per cent of people aged fifty with no pain have a protrusion. The case for surgery is built from the physical examination, the way things change over time and the match between the affected level and the symptoms. Never from the image alone.
"A herniated disc never heals." Two out of three resorb.
"You need complete bed rest." This is the advice that has done the most harm. Every current guideline recommends staying active within what the pain allows. Prolonged time in bed weakens, stiffens and delays recovery.
"It was bad posture, or the mattress." The factors genuinely associated with it are age — the peak is between thirty and fifty — smoking, excess weight and the load work places on the spine over the years. In most cases there is no single culprit, and looking for one does not help.
Stem cells to regenerate the disc. The United States regulator has issued specific consumer warnings about regenerative medicine products promoted for these indications. If this is offered to you as established treatment, ask to see the clinical trial behind it.
What will happen at the appointment
Less than you fear. A sensible neurosurgeon will spend most of the time examining you: reflexes, strength in each muscle group, sensation by territory, straight leg raise. That examination is worth more than the MRI, because it says whether the image and the patient agree.
Then they will want to know about time. How many weeks ago it started, whether the pain is improving or worsening, what you have tried and with what result. A herniated disc is treated over weeks, not in a single snapshot.
And if all this has been going on for less than six weeks, you have no warning signs and your strength is intact, the most likely answer — and the right one — is that it is not yet time to decide anything surgical.
Questions worth writing down before you go
- Does the level shown on the MRI explain exactly the path my pain follows?
- Do I have weakness on examination, or only pain?
- If we wait, what exactly are we waiting for, and until when?
- What signs should bring me back before the next appointment?
- If I have surgery, what is the realistic goal: the leg pain, the back pain, or both?
- How many of these operations do you do a year?
The questions people ask most
Does a lumbar herniated disc heal on its own?
In the vast majority of cases, yes. Between 85 and 90 per cent of symptomatic herniated discs stop hurting within six to twelve weeks. And two out of three physically resorb: the herniated material disappears from the MRI without anyone taking it out.
How long does a herniated disc take to resorb?
It is a process of months, not days. Relief from the pain usually arrives well before the herniation disappears on imaging. That is why repeating an MRI a few weeks later almost never changes a decision: the image lags behind the patient.
What happens if I do not have surgery?
In most cases you get better anyway, only more slowly. What cannot be put off is a herniated disc with progressive weakness or with loss of bladder or bowel control. Beyond that, waiting is a valid medical decision, not a postponement.
When does a lumbar herniated disc need surgery?
There is one urgent indication — cauda equina syndrome — and one firm indication: significant weakness that does not improve or that is progressing. The rest is a decision to be talked through: pain that persists beyond six to eight weeks of properly delivered treatment, in someone whose scan matches the physical examination, and whose quality of life is seriously affected.
Is herniated disc surgery dangerous?
Microdiscectomy is one of the most common and best studied operations on the spine, and in trained hands it has a low complication rate. But "low" is not "zero", and no operation is a formality. You deserve to have the specific risks in your case explained, not a general figure.
What exercises should I avoid?
While the radiating pain is active it is best to avoid bending the trunk forward under load, lifting weight from the floor with a rounded back, and sit-up style abdominal exercises. Walking, on the other hand, is almost always allowed and does you good. What is not advisable is staying still.
What is the best way to sleep?
On your side with a pillow between your knees, or on your back with your knees bent and something underneath them. There is no magic position: the good one is the one that does not wake the pain.
My MRI says "protrusion" and not "extrusion". Is that better?
These are grades of how far the disc material has come out. Counter-intuitive as it sounds, extruded herniations — the ones that have come out further — tend to resorb better, because they are more exposed to the immune system. The word in the report predicts neither severity nor the need for surgery.