While less common for a person to have sciatica in both legs, I do see this alarming problem quite often as well as hearing a lot of stories from my online readers. From experience, I know that I must take extra care when assessing and treating anyone with sciatica in both legs. Today, we’ll discuss what might cause sciatica in both legs and what to do about it.
What Might Cause Sciatica in Both Legs?
Sciatica in both legs is usually caused by the same problems that cause sciatica in one leg. However, there are also several unusual causes that can lead to sciatica in both legs.
First, let’s recap on the most common causes of sciatica in one OR both legs:
- A disc bulge or herniation: The tough outer part of the intervertebral discs in the spine can develop micro-tears over time through repetitive movements under load.
These micro-tears can develop into “bulges”, which occur when pressure causes the inner material in the disc to push into these weakened zones. The bulges can encroach on the tight spaces that the nerve roots run through.
In a worst-case scenario, the inner material of the disc can actually leave the side of the disc through these weakened areas, causing a chemical reaction around the nerve root leading to sciatica. This often gets worse when a person bends forward, as pressure on the front of the disc causes the inner material to “bulge” backwards towards the nerve root, irritating it and causing sciatica symptoms. An unfortunate side effect of physics!
- General age-related changes to facet joints and discs: As we age, our discs dry out and lose height, the bone around our joints thickens, our joints become stiffer and we lose the cartilage that helps to lubricate movement in our spines.
While not necessarily painful on their own, these changes equate to a smaller and less lubricated space for the nerve roots to exit the spine from. This can cause them to become compressed. When this compression becomes more severe, it leads to a condition called “spinal stenosis” (more on this later).
- Piriformis syndrome: In some people, the sciatic nerve runs through a muscle in the buttock region called the Piriformis. When this muscle gets tight, the nerve can become compressed in the buttock, causing similar pain and numbness to the other types of sciatica. It would be VERY rare for someone to have piriformis syndrome in both legs.
- Fractures: In rare cases, a fracture of one of the vertebrae can cause a compression on a nerve root. This can happen following trauma, like a fall, but if someone has a condition called “osteoporosis” then fractures can occur spontaneously. Osteoporosis is a condition that causes a thinning of the bones and is more common in women and the elderly. Fractures are usually a more serious cause of sciatica and can lead to sciatica in both legs.
- Tumour or growth: Very rarely, a cyst, tumour or other lesion can occur in the spine which then leads to a nerve root compression. This type of problem is luckily not very common. We will talk about “red flags” for tumours later in this post. If you’re really worried about this being a cause for your sciatica, please go and seek help from your doctor, who can hopefully put your mind at rest.
How Do These Problems Cause Sciatica in Both Legs?
Any of the above problems can lead to sciatica in both legs instead of the usual symptom of sciatica in one leg. Whether the problem causes sciatica in one or both legs is determined by the location of the issue.
Let’s take a disc bulge, for example.
If the disc bulge happens to be on the right side of the disc, then the bulge will irritate the right nerve root only, and the person will likely experience right leg symptoms.
If the disc bulge happens to be on the left side of the disc, then vice versa for the left leg.
However, if the disc bulge happens to fall in the middle of the back of the disc, the bulge may well make contact with BOTH nerve roots, causing sciatica in both legs.
There may also be multiple disc bulges – some on the right and some on the left – which can cause sciatica in both legs too.
This is also the case for degenerative disc disease and aging changes to the spine.
Although extremely rare, a tumour can often cause sciatica in both legs if it is affecting the central spinal cord. However, in three years of seeing sciatica clients daily, I have only ever had ONE person unlucky enough to have a spinal tumour as the cause of their sciatica!
What Else Might Cause Sciatica in Both Legs?
Spondylolisthesis: Imagine your spine as a stack of bones stacked one on top of the other. A spondylolisthesis occurs when one of these bones “slips” forward, usually as a result of advanced aging changes. This can also happen as a result of trauma, although this is rare.
Because of such a significant structural change, both nerve roots or the central spinal cord can be trapped in the spine, causing sciatica in both legs.
Spinal stenosis: This is probably the most common cause of sciatica in both legs.
Spinal stenosis occurs due to widespread degenerative changes throughout the lower back. These changes lead to a narrowing of the spaces where the nerves are, causing a low-level compression that worsens over time.
For people with spinal stenosis, walking or standing upright tends to be their most painful movement or position. This is because of gravity – when the person is upright, the compression on the nerves is worse. They can usually alleviate their pain by leaning forwards, as you do when you lean on a shopping trolley, for example.
This problem leads to sciatica in both legs that usually affects the calves and presents as a chronic, throbbing sensation with or without pins and needles.
Cauda Equina Syndrome: This condition is the main one we need to be aware of and look out for! Cauda equina syndrome occurs when the bottom part of the spinal cord (called the cauda equina) is compressed, usually by a disc.
Not only will the sufferer experience sciatica in both legs, but they will also likely experience an array of alarming symptoms:
- Altered sensation to the “saddle” area around your bottom and privates
Do you have any numbness in the area of your bottom that touches the seat when you sit down? Do you have any numbness when you wipe your bottom?
This symptom can occur when the nerves that supply the skin around this area of the body become compromised. It can indicate a nerve compression which requires immediate attention.
- Loss of control of bladder or bowel function. This includes both incontinence and retention (not being able to pee)
Do you have any problems with your bladder and bowel function? Do you try to pee but find it hard to start the flow? Have you had any “accidents” recently where you have gone without knowing?
Again, this can indicate a serious compression in the lowest nerves coming from the spine. These nerves control bladder and bowel function. If the compression is not relieved quickly, there are usually permanent consequences.
- Loss of strength in the legs
Do you feel like your knee, hip or ankle wants to give way when you walk? Do you feel like you are losing strength in your limbs?
A loss of strength in the legs occurs when the innermost fibres of the nerve are squashed. This prevents the signals from reaching their target muscle normally.
In cauda equine syndrome, you may also experience the pins and needles and numbness associated with routine sciatica.
Cauda equina is a medical emergency and requires immediate investigation. It is best practice to contact your local emergency centre if you have any of these symptoms. Do this as quickly as you can as the quicker you act, the better the outcome is likely to be!
What Can I Do About Sciatica in Both Legs?
Treating sciatica in both legs is tricky and treatment plans will differ depending on the cause.
Obviously, if your sciatica is caused by a serious issue like cauda equina, you will likely need surgery to release the spinal cord. However, the next part of this article will be directed at those who have a less serious cause of sciatica in both legs.
I read a lot these days about treating sciatica by mobilising and stretching the non-painful leg – and this is an approach I often use myself – however, what are you supposed to do if both legs are painful?!
If you’ve followed my work for any length of time, you’ll know I advocate a pain-free exercise approach when treating sciatica.
When stretching either leg is painful, you should avoid those stretches all together. Instead, you should focus on performing whatever non-painful movements of the lower back you can manage.
I discuss the process of choosing a Movement Preference and putting it into action in detail in Steps 3 and 5 of The 7 Steps to Overcome Sciatica.
However, you can see a brief rundown of this technique on my blog by clicking here!
If stretching one of your legs is less painful than the other, try very gently performing some of the stretches from this article here on the less painful of the two legs.
I will say it again: don’t push into pain! It will make your symptoms WORSE and this is the reason why so many healthcare professionals struggle to help people with sciatica!
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So, we have learned about the possible causes of sciatica in both legs and read about what causes pain to occur in both sides rather than just one for some unlucky individuals.
Although sciatica in both legs is difficult to treat, it isn’t necessarily a life sentence!
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