Leg pain is a common complaint, but sometimes it can be hard to determine the source of the issue at times. Was that the extra mile you added to your walk too much, too quick? Maybe sitting on your leg all day while at work wasn't the best idea? Or could it be something else entirely — a problem that doesn't even involve your leg at all?

"One of the most misunderstood sources of chronic pain I see is back-related leg pain," says Dr. Jonathan Paek, a pain medicine management physician at Houston Methodist who specializes in spine issues. "Whether it's hip pain, knee pain or leg pain, patients are often surprised to learn that you can have a back problem without any back pain and that their issue might actually be in their lumbar (or lower) spine."

In fact, some of the most common spine issues cause back pain only around 30% of the time. Instead, the first sign of these issues is often pain felt somewhere down the leg, which is why understanding the connection between back problems and leg pain is key to getting the right treatment.

When back problems cause leg pain

There are two primary back-related causes of leg pain — disk herniation and spinal stenosis. Both have distinct characteristics.

Herniated disk

Between each set of vertebrae in the lumbar spine lies a cushiony disk that helps absorb the pressure placed on these bones. A herniated disk occurs when the soft, gel-like center of the spinal disk bulges or pushes through its outer layer and causes irritation to nearby structures.

"Not all herniations are the same," adds Dr. Paek. "When the disk presses on a nearby nerve that then travels down the leg, it's called radiculopathy. This type of pain is less about a change to the structure of the spine and more about the inflammation that occurs from nerve irritation."

This type of pain can be related to either pressure on the nerve or localized inflammation that can irritate the nerve root. (Related: When Is Surgery Needed for a Herniated Disk)

Spinal stenosis

"Stenosis simply means narrowing or decreased space," explains Dr. Paek. "Spinal stenosis, then, is a narrowing along the spinal column."

When this happens, it can lead to compression of nearby nerves — limiting blood flow and causing irritation that leads to leg pain. Spinal stenosis in the lower back is more common in older adults and is typically position-dependent, worsening when standing upright and improving when sitting or leaning forward.

"Sitting or hunching over opens up space in the spine, so the nearby nerve is less likely to be compressed and cause pain down the leg," explains Dr. Paek. "But when the person stands up, the pain comes on as space in the spine is choked off and the nerve becomes compressed."

He adds that this is more casually referred to as the "shopping cart sign" of spinal stenosis — where a person notices their leg pain when they start walking around the grocery store, but this dissipates if they hunch forward to lean against the handlebar of their shopping cart.

What's not a back issue?

Not all leg pain is caused by a back problem, of course. Musculoskeletal issues like strains, tendinitis, bursitis, osteoarthritis and stress fractures can lead to leg pain. Circulatory problems, like peripheral artery disease (PAD) and deep vein thrombosis (DVT), can cause leg pain as well.

Nerve issues can closely mimic the symptoms of a back-related problem, highlighting the importance of proper evaluation and diagnosis. "Diabetic neuropathy is an example of this, where high blood sugar levels lead to nerve damage, over time, which often starts as leg pain," explains Dr. Paek. (Related: What Are the Early Warning Signs of Neuropathy?)

Sciatica is another example, and this is a condition that can be very misunderstood. While sciatica can be caused by a herniated disk or spinal stenosis, this isn't always the case. "The cause can be anything that irritates the sciatic nerve, including injury anywhere along the path of this nerve," adds Dr. Paek. "Maybe you had a bad ACL tear and trauma behind the knee affected it. Or even something like a really tight piriformis muscle is pinching the sciatic nerve."

Signs that leg pain might be a back issue

Certain characteristics can help differentiate back-related leg pain from other sources. These include:

• Unusual sensations: Burning, tingling and numbness are hallmark signs of nerve involvement
• Positional changes: Pain that worsens when standing and improves when bending forward could point to a spine problem
• Persistent pain despite joint treatment: According to Dr. Paek, "We occasionally see patients who've had hip or knee replacements without relief, only to discover a back issue was the root cause."

If you're struggling with leg pain, especially if it's accompanied by nerve-related sensations, is unexplained or doesn't improve despite treatment, consult a pain or spine specialist. "A thorough evaluation is crucial," says Dr. Paek. "Imaging and other tests can help confirm or rule out whether the issue stems from a problem in the spine."

While nerve damage from a back problem is rare, the chronic pain these issues cause when left untreated can lead to physical inactivity, a decline in mental health and more. Seeking prompt care can help diagnose the underlying issue and determine the most effective treatment plan.

Treatment options for back-related issues

The good news is that most lower back issues don't require surgery. "About 85%-90% of cases can be managed non-surgically," says Dr. Paek.

Treatment for spine problems, such as a herniated disk or spinal stenosis, typically includes a combination of:

• Physical therapy, particularly exercises aimed at strengthening core muscles, to reduce pressure on the spine
• Injections, including targeted treatments to reduce inflammation or inappropriate nerve signals

(Related: In Need of Back Pain Relief? Try Some Exercise)

"If we think we can prevent surgery, we'll take the patient down the non-surgical treatment pathway," adds Dr. Paek. "But if we think surgery is ultimately unavoidable, we will get them to surgery as soon as possible, so we don't delay symptom improvement."

Lifestyle changes are also important for treatment of spine problems, not to mention prevention of these issues.

"Core muscle strength and weight management are the most important things you can work on at home to improve pressure on your disks," says Dr. Paek. "To improve your symptoms — or your overall chance of avoiding a disk issue in the future — it's important to do core exercises regularly and maintain a healthy weight."

He adds that smoking is another significant risk factor for spine issues.

"There's a lot a person can do to help improve their symptoms, from physical therapy and injections to these personal lifestyle changes they can make themselves at home," says Dr. Paek. "The most important step is just getting evaluated — an accurate diagnosis is required to come up with the most effective treatment plan and prevent the patient from receiving treatment for the wrong issue."