My leg is numb. Is it a herniated disc or spinal stenosis?

The two names that come up when you search "leg numbness lower back"

Key points in 30 seconds

1. Leg numbness usually happens because a nerve running from the lower back to the leg is being pinched. What pinches it is mainly one of two things: a herniated disc or spinal stenosis.
2. With a herniated disc, the cushion between the vertebrae pushes out and presses on the nerve. With spinal stenosis, the canal the nerve passes through has narrowed over the years.
3. The most useful clue is one question: does it hurt more when you sit, or when you walk?
4. But the two often occur together, and if stopping brings relief regardless of posture, it may be a problem with the blood vessels in your legs. Confirmation comes from examination and imaging.
5. Once it has a name, the paths split. For a disc, the goal is getting through the time it takes to be reabsorbed; for stenosis, it's gradually increasing how far you can walk.

What we often hear

• "Reading online, it sounds like a disc, but it also sounds like stenosis."
• "A tingling runs down from my buttock to my calf."
• "Every clinic tells me something a little different."
• "Whichever it is, isn't the treatment about the same?"

A tingling, numb feeling that starts in the buttock and runs down the back of the thigh and along the calf.

When you search, two names keep coming up: herniated disc in the lower back, and spinal stenosis. Reading the symptom descriptions, both sound like you, which makes it even more confusing.

Why does it matter which one it is? Because different names mean different ways of waiting, different treatment goals, and different postures to watch out for.

Two things press on the nerve

Let's start with the explanation we always give in the clinic.

Leg numbness usually happens because a nerve running down from the lower back to the leg is being pinched. Mainly two things pinch that nerve: a disc, or stenosis.

A herniated disc is when the inner material of the cushion between the vertebrae pushes out and presses on the nerve. It often starts relatively suddenly.

Spinal stenosis is when the canal the nerve passes through has narrowed. As strain builds up from years of using your back, bone grows extra spurs and ligaments thicken. Little by little, the canal narrows and squeezes the nerve. It usually comes on gradually.

Think of a hallway. A herniated disc is like a crate that suddenly rolled into the hallway; stenosis is like the hallway walls pushing inward a little more each year. Either way the person passing through (the nerve) is cramped, but the way to clear it is different.

Clues you can gauge at home

Clue	Disc side	Stenosis side
Age	Common even in your 30s–50s	Common from your 50s–60s on
When it gets worse	Sitting for a long time, bending forward	Standing or walking for a long time
What brings relief	Standing or lying down	Sitting or bending forward
Coughing or sneezing	May send a jolt down the leg	Often no clear change
One side or both	Usually one leg	Both legs may feel heavy together
Onset	Relatively sudden	Gradual, walking distance slowly shrinks

If you had to pick just one, it's this: does it hurt more when you sit, or when you walk?

If it gets worse when you sit and shoots down more when you bend forward, we think of a disc first. If your legs get heavy as you walk so you have to stop, and sitting or bending forward quickly eases it, that points to stenosis. More clues on the stenosis side are in the post on legs going numb when you walk.

The table isn't the answer

These clues are only a guess, not a diagnosis.

What's more, in reality the two often occur together. Here's something we often say in the clinic: "If it isn't one injury from a sudden fall, but years of using your back, it's rarely just one spot that's worn." A disc problem can overlap with stenosis in the same back, or there can be a little trouble at several levels.

So confirmation comes from examination and, if needed, imaging.

It may be neither

When walking, does leg pain make you stop, but just stopping brings relief, regardless of posture, whether you bend forward or simply stand? Are your feet unusually cold or pale?

If so, it may be a problem of narrowed blood vessels in the legs. In that case, a blood vessel check comes before the back.

With these signs, we don't wait, whatever the name

• You have trouble urinating or with bowel movements, or it's become hard to hold them in
• Your buttocks, groin or inner thighs, the area a bicycle seat touches, have gone numb
• Weakness in your ankles or toes is steadily getting worse

Whether it's a disc or stenosis, if you have any of these, you need a surgical assessment right away. If you come to us, we'll tell you the same thing and refer you right away.

Once it has a name, the paths split

If it's a herniated disc, the body often clears away the pushed-out cushion on its own, given time. There's even research showing that badly ruptured discs are reabsorbed more readily (the disc reabsorption post). So the goal is to make that time bearable, and adjusting habits like sitting for long periods and bending forward becomes important.

If it's spinal stenosis, rather than waiting for the narrowed canal to widen on its own, the goal is to help the nerve cope within it and gradually increase how far you can walk. You need to break the cycle of walking less because it hurts, and then being able to walk less because you walked less. That's why the technique of walking with rest breaks is a big part of treatment (the spinal stenosis evidence post).

We start by getting the name right

First, we sort things out. We ask in detail when it gets worse and what brings relief. We check the nerves with a straight-leg-raise test while you lie down, and by examining leg strength, sensation and reflexes. If needed, we confirm with MRI which level has what, in partnership with the radiology clinic on the 2nd floor of the same building. If a blood vessel problem is suspected, we refer you for that test first.

Second, we treat according to the name. We ease leg pain and tension around the lower back with acupuncture and pharmacopuncture (herbal acupuncture), and, within the limits of what the nerve check allows, work on stiff movement with Chuna (Korean manual therapy). For a disc, we set lifestyle adjustments to get through the reabsorption time; for stenosis, a walking prescription to increase your walking distance.

Third, we check with records. Before treatment, we note your leg pain score, how far down the numbness goes, and how many minutes you can walk without resting, and compare them at each set point. If things aren't heading in a better direction, we don't repeat the same treatment; we guide you to the next path.

What changes

Instead of nights spent searching "disc or stenosis?" over and over, days when you know the name of your leg numbness and the plan that fits it.

That's what we're aiming for.

How fast you recover differs from person to person depending on the cause, how badly the nerve is pinched, and how long it has hurt.

Today's takeaway

With leg numbness, the path becomes clear once you name it first. Whether it hurts more when you sit or when you walk is the first clue, and confirmation comes from examination and imaging.

Today, write down just four lines.

• Whether it hurts more when sitting or when walking
• Whether bending forward eases it or makes it shoot down more
• Whether coughing sends a jolt down your leg
• Whether it's one side or both

If you bring this note with you, the visit to find the name is already about half done.

For questions or appointments, message us in English through the messenger at the bottom right of the page, or call +82-53-716-1175.