What Is Foraminal Stenosis?

Medically Reviewed by Dan Brennan, MD on May 15, 2021

Your spine has 33 bones that form around your spinal cord. Between each bone is a space that allows nerves to spread throughout your body. When these openings narrow, you may suffer from what's called foraminal stenosis. This can cause pain, weakness, and other problems with nerves that are connected in your spine.

Understanding Your Spine

The bones in your spine are called vertebrae. The openings in your spinal column between these vertebrae have a specific amount of space between each bone. Your lowest vertebrae, the sacrum and coccyx, are fused together. The rest of your vertebrae, however, allow for a range of movement.

Your spine’s curved design absorbs impacts to your body to protect the nerves that fit between each bone. In between your vertebrae are joints made of cartilage. This connective tissue allows your vertebrae to move against one another without causing damage.

Intervertebral discs are round cushions made of a gel-like substance that sits between your vertebrae. Ligaments also connect your vertebrae together and hold your spine in place.

Your spine has 31 pairs of nerves that branch out in your vertebral openings, also called foramen. These nerves carry messages from your body to your brain. For example, if you touch something hot, your nerves transmit the message to your brain and your brain tells you to stop touching it.

Causes of Foraminal Stenosis

Over time, your cartilage and spinal cushions may wear down, and the spaces between your bones can shrink. Blockages may also make your spinal column smaller, taking away the space your nerves need to transmit messages.‌

Many things can lead to blockages or shortening of space in your spinal column:

  • Degenerative arthritis in your spine may cause bony spurs that block spinal openings.
  • The wearing down of your intervertebral discs may cause bulging between your vertebrae.
  • Ligaments surrounding your spine may enlarge.
  • Vertebrae can slip out of place.
  • Growths like cysts or tumors may appear.
  • You may develop health conditions like Paget disease that affect your bones‌.
  • Congenital health conditions like dwarfism can also shorten the space.

Symptoms of Foraminal Stenosis

Nerve compression can happen between any vertebrae on your spinal column. Compressed nerves lead to pain and other symptoms throughout your body. It may affect one, a few, or all of your vertebrae, depending on the location of the affected nerves. ‌

If you have foramen in the spine, you may experience:

  • Pain in your neck or lower back that worsens slowly over time
  • Numbness or pins and needles in your arms or legs
  • Weakness 
  • Sciatica pain

Diagnosing Foraminal Stenosis

If you suspect you have foraminal stenosis, talk to your doctor. After looking at your medical history, they look for limitations in your movement, ask about pain and numbness, and check your reflexes.

If your doctor suspects foraminal stenosis, there are several procedures used for a formal diagnosis:

  • X-rays help assess your vertebrae and identify or rule out growths, injuries, and abnormalities.
  • Magnetic resonance imaging (MRI) shows damage or disease that affects the cartilage and cushions between your discs.
  • Computerized tomography (CT) scans give outlines of all the structures that surround your spinal canal, showing any impacts on your nerves.
  • A Myelogram is a procedure where your doctor uses a dye to show the movement of fluid between individual discs in your spine. Once they inject dye, they use a CT or MRI to see pressure points affecting your nerves.‌
  • Bone scans identify fractures, growths, infections, and arthritis that impact your spinal column.

Treating Foraminal Stenosis

At-home care. If you’re in the early stages of foraminal stenosis, your doctor may recommend several options for treatment, including:

  • Pain medication like aspirin or ibuprofen
  • Corticosteroid injections
  • Limiting certain activities that aggravate your condition
  • Physical therapy or strengthening exercises‌
  • Braces that alleviate pressure to your spine

Surgery. If your condition is causing severe pain or impacting your quality of life, your doctor may suggest surgery on the spine. The surgery, called a foraminotomy, may be more or less invasive depending on the degree of damage to your spine. 

A neurosurgeon works with specialized nurses to perform a foraminotomy, which usually takes several hours. Here’s what you can expect during the surgery:

  • You’ll lie on your stomach.
  • Anesthesia puts you to sleep so you don’t feel pain or discomfort during the procedure.
  • Nurses monitor vital signs like your heart rate and blood pressure.
  • Your surgeon makes a small incision beside the vertebrae on the side of your body affected by symptoms.
  • X-rays and a microscope help guide the procedure.
  • Your surgeon uses special tools to move muscles and ligaments blocking the opening, so they have a clear view of the vertebrae.
  • Any blockage is removed, or bulging discs are repaired.‌
  • Your doctor may need to remove a portion of your vertebrae to allow more room for your nerves.
  • Your muscles and ligaments move back into place and the incision is closed with stitches.

After foraminal stenosis surgery, you usually resume a normal diet and activity. You may need to rest for a few days following the procedure and allow the surgical site to heal. Depending on the reason for your surgery, your doctor may recommend physical therapy.

Show Sources


Cedars-Sinai: “Foraminal Stenosis.”

Cleveland Clinic: “Spine Structure and Function.”

Johns Hopkins Medicine: “Foraminotomy.”

SONSA (Southern Oregon Neurosurgical & Spine Associates): “Spine Conditions: Lateral Recess/Foraminal Stenosis.”

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