10 Known Causes of Lumbar Radiculopathy

2. Sciatica

Sciatica is a common cause of lumbar radiculopathy. You feel it when a nerve root in your lower back gets pressed or irritated and sends pain down your leg. The sciatic nerve forms from several nerve roots in the lower spine. It runs from your lower back through your buttock and down the back of your leg.

When one of these nerve roots becomes compressed, the pain can travel along this path. In most cases, a herniated disc causes the pressure. Age-related wear and tear in the spine can also narrow the space around the nerves, which can squeeze the nerve root and trigger symptoms.

You may feel sharp or burning pain that moves from your lower back into one leg. Some people notice tingling, numbness, or weakness in the leg or foot. The pain often affects only one side of your body. Bending, lifting, sitting for long periods, coughing, or sneezing can make the pain worse. Sciatica describes this pattern of nerve pain, but the source usually begins in your lower spine.

3. Degenerative Disc Disease

Degenerative disc disease happens when the discs between your spinal bones break down over time. These discs act as cushions and help your spine move with ease. As you age, they lose water and become thinner, which reduces their ability to absorb shock.

A worn disc may bulge or tear, which can narrow the space where a spinal nerve exits. If the disc presses on a nerve root in your lower back, you may develop lumbar radiculopathy. You might feel sharp pain that travels from your lower back into your buttock and down your leg.

Common features include ongoing low back pain, pain that gets worse with sitting, bending, twisting, or lifting, stiffness after rest, and numbness or tingling in your leg if a nerve is compressed. The L4-L5 and L5-S1 levels are often affected because they carry much of your body weight. Daily wear and tear, past injuries, and smoking can speed up disc breakdown.

4. Bone Spurs

Bone spurs are small bony growths that form along the edges of your bones. In the spine, they often develop when joints wear down from arthritis or long-term stress. Your body builds extra bone to protect the joint, but this extra bone can cause problems.

Many bone spurs do not cause symptoms. You may only learn about a bone spur after an X-ray for another reason. When a bone spur narrows the space where a nerve exits your spine, it can lead to lumbar radiculopathy. You may feel sharp pain that travels from your lower back into your buttock and down your leg. Some people notice tingling, numbness, or weakness in the leg or foot. Common effects include leg pain that worsens with standing or walking, numbness or pins and needles in the leg, and muscle weakness in severe cases.

Age-related changes increase your risk. Loss of disc height and joint damage can make bone spurs more likely. As these changes build over time, they can reduce the space around your spinal nerves. Treatment depends on your symptoms, and may include pain relievers such as nonsteroidal anti-inflammatory drugs, physical therapy, weight control, and in severe cases, surgery to remove the spur and relieve nerve pressure.

5. Tumors of the Spine

Tumors can grow inside your spine or spread there from another part of your body. When this happens, the growth can press on a nerve root and lead to lumbar radiculopathy. Your spinal cord runs through a canal made of bone, and nerves exit through small openings between the bones.

A tumor in this tight space can crowd these nerves and cause pain. You may feel sharp or burning pain that travels from your lower back down your leg. Some people notice numbness, tingling, or muscle weakness. In some cases, pain does not improve with rest and may slowly get worse.

Spinal tumors can be primary, which means they start in the spine, or metastatic, which means cancer spreads from another area to the spine. Doctors use imaging tests such as MRI or CT scans to look for a mass. Treatment depends on the type and size of the tumor and may include surgery, radiation therapy, chemotherapy, or other cancer care.

6. Spinal Stenosis

Spinal stenosis happens when the space inside your lower spine becomes narrow. This narrowing can press on the nerve roots that travel into your legs. When pressure builds, you may feel pain, tingling, or numbness along the path of the affected nerve.

Age-related changes often cause this problem. Thickened ligaments, enlarged joints, or bulging discs can reduce the space around your nerves. Some people are born with a smaller spinal canal, which raises the risk of symptoms later in life. You may notice leg pain that worsens with standing or walking. Many people feel relief with sitting or leaning forward, since this position can open the spinal canal slightly and reduce nerve pressure.

Common symptoms include pain that travels from your lower back into your buttock or leg, numbness or pins and needles in your foot or calf, and weakness in one or both legs in more severe cases. Doctors often link this condition to lumbar radiculopathy because the narrowed space irritates nerve roots.

7. Spondylolisthesis

Spondylolisthesis happens when one bone in your spine slips forward over the bone below it. This shift can narrow the space where your spinal nerves exit. When the slipped bone presses on a nerve root, you may feel sharp pain that travels from your lower back into your buttock and down your leg. This nerve pain is a common cause of lumbar radiculopathy.

You might also notice numbness, tingling, or weakness in one leg. Several factors can lead to this condition, including age-related wear and tear of the spine, stress fractures from sports that strain the lower back, a defect in part of the vertebra present since birth, and injury or trauma. In adults over 50, joint wear is a common cause.

In younger people, repeated back extension in sports such as gymnastics or football can create small fractures that allow a vertebra to slip. Your pain may worsen with standing or walking for long periods. Some people feel relief with sitting or bending forward, since these positions can reduce pressure on the nerve.

8. Scoliosis

Scoliosis is a sideways curve of your spine. It often begins in late childhood or the early teen years. In many cases, doctors cannot find a clear cause, and this type is called idiopathic scoliosis. A curved spine can change how weight spreads across your lower back.

Over time, uneven pressure may narrow the spaces where nerves leave your spine. When a nerve root becomes pressed or irritated, you may develop lumbar radiculopathy. You might feel sharp or burning pain that travels from your lower back into your leg, along with numbness, tingling, or muscle weakness in one leg.

These symptoms occur because the curved spine can twist and reduce space in the nerve openings, often more on one side. Scoliosis can also lead to early wear of spinal discs and joints, which may further squeeze nearby nerve roots. Not everyone with scoliosis develops nerve pain, but risk increases with moderate to severe curves or worsening changes over time.

9. Spinal Infections

Spinal infections can irritate or damage the nerves in your lower back. When this happens, you may feel sharp pain that travels from your lower spine into your buttock or leg. This pain can feel similar to other causes of lumbar radiculopathy.

Osteomyelitis is an infection in the bone, and discitis is an infection in the space between the bones of your spine. Both conditions often begin when bacteria spread through your bloodstream from another part of your body. In some cases, infection follows surgery, an injection, or a nearby wound.

You may notice constant back pain that does not improve with rest, along with fever, chills, tiredness, or tenderness over the lower spine. The risk is higher in people with diabetes, weak immune systems, recent spine injuries, or long hospital stays.

10. Spinal Trauma or Injury

Spinal trauma can damage the nerve roots in your lower back. When this happens, you may develop lumbar radiculopathy. The injury can press on or irritate a nerve as it exits your spine. Common causes include falls, car crashes, sports injuries, physical assaults, and workplace accidents.

A sudden blow to your back can shift bones, tear soft tissue, or cause swelling. Even a small change in bone position can narrow the space around a nerve root. This pressure can trigger sharp pain that travels from your lower back down your leg. You may also notice numbness, tingling, or weakness in the leg or foot on the affected side.

Symptoms depend on which nerve root is injured. In more severe cases, trauma can cause fractures or damage to the spinal cord. Swelling and bleeding after an injury can increase pressure inside the spinal canal.