Spinal Stenosis

Spinal stenosis happens when the space around the nerves in your lower back narrows. The narrowing can occur at the central part of the back (called the spinal canal) or where the nerves exit the spine to travel down the legs. The narrowing may put pressure on the nerves. This can be something you’re born with, or it can develop over time as part of the natural ageing process. The narrowing occurs due to changes in the bones, discs or ligaments of the spine. It is more common to see this problem in people over the age of 60. Many people have spinal stenosis seen on scans without having any symptoms. Treatment is based on your symptoms rather than scan findings.

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The main symptoms of spinal stenosis are:

• Pain that starts in the lower back or buttock and travels down one or both legs. Some will experience severe symptoms and others mild symptoms
• Some patients will feel heaviness or a cramping sensation in the legs
• Pins and needles or tingling affecting a part of the leg
• Some people notice weakness or a feeling that their legs may give way. If you notice significant weakness, seek advice from a healthcare professional
• These symptoms usually come on with prolonged standing and ease with sitting or bending forwards. This is because sitting or leaning forwards usually creates more space around the nerves, which can temporarily reduce irritation

Symptoms often affect both legs, although one side may feel worse. Many people notice their leg pain improves when they sit down or lean forward while walking. This occurs as sitting or leaning forward positions opens the space around the nerves. Although back pain can be present, the main issue is usually the pain, heaviness, or tingling in the legs.

Know When to Seek Help

If you have symptoms that could suggest cauda equina syndrome, seek urgent medical assessment. This is usually through A&E because early assessment is important. If untreated, it can sometimes cause permanent problems affecting the legs, bladder, bowel or sexual function. You can download a cauda equina syndrome information card for further information.

There are many causes of back pain. Although the symptoms can be distressing, most do improve with time. There are circumstances where a medical opinion is appropriate. If you are experiencing any of the following, please contact 111 or your GP for advice.

• New weakness in one or both legs, or difficulty walking or coordinating your legs.

• Severe pain that is worse at night and not relieved by changing position

• Fever (temperature above 38 degrees) and severe back pain

• Pain that started after a serious accident, such as after a car accident

• Back pain and a history of previous cancer

• Back pain following a minor injury or lift if you have osteoporosis

Do I need further investigations?

Many people ask whether they need a scan. It is natural to think an MRI scan would be helpful to guide management and provide a diagnosis. In most circumstances it does not change treatment. An MRI scan shows detailed images of the back, however a scan is not usually needed to diagnose spinal stenosis. Many people have spinal stenosis seen on scans without having any symptoms. Treatment is based on your symptoms rather than scan findings.

There are circumstances where further investigations are necessary. For example, suspected cauda equina syndrome, significant new muscle weakness, a serious underlying condition, or persistent spinal stenosis symptoms. A healthcare professional would recommend further investigation in these contexts.

The information below is reproduced from NHS England's BestMSK patient advice to help explain what an MRI scan can and cannot tell us, and when an MRI may be appropriate.

Some important things you need to know about what an MRI scan can tell us and when it is appropriate

• MRIs provide a picture of the anatomy of the spine.

• MRIs cannot tell how someone feels and are not a diagnosis.

• MRIs can be used to plan treatment with you and rule out serious conditions such as cancer or fractures.

• MRIs are rarely needed for people with back or neck pain.

• MRIs should be requested after assessment by a specialist.

Some important things you need to know about your MRI scan report

• Some of the medical words used in MRI reports can be complex and may sound scary.

• For example, eight out of ten people aged 50 or over with NO pain have something called ‘degeneration of discs’ noted in their MRI report. However, findings such as this are more common as we become older and can be signs of a naturally maturing spine.

If you have any questions about having an MRI scan or need clarification on the report of an MRI scan, please discuss these with the clinician who sent you for the MRI.

Lifestyle factors that influence health

Symptoms of spinal stenosis can be influenced by your overall health. Physical activity levels, carrying extra weight, long-term stress, sleep quality and smoking can all affect recovery. Maintaining good general health can support recovery and improve long-term spine health. More support with health and lifestyle factors can be found on our Your Musculoskeletal Health webpage.