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Dr. Chrysoula I. Liakou MD, PhD
- Treated online: Assessment online. A doctor can check back pain and sciatica for the warning signs; suspected cauda equina syndrome needs an emergency MRI scan, and usually surgery, in hospital.
- What it is: squeezing of the bundle of nerve roots at the base of the spine that serve the bladder, bowel, genitals and legs, most often by a large slipped disc.
- How rare: about 1 to 3 in 100,000 people a year, but it is a surgical emergency.
- Warning signs: numbness around the genitals or bottom, new problems peeing or controlling your bowels, and sciatica or weakness in both legs.
- Emergency: call 112 or go to an emergency department now for any of these warning signs; do not wait to see if they pass.
Do not book a video appointment if you have back pain or sciatica with numbness or tingling around your genitals, bottom or inner thighs, new difficulty starting to pee or not feeling your pee, loss of bladder or bowel control, sciatica in both legs, weakness or numbness in both legs that is severe or getting worse, or new loss of sexual feeling. Call 112 or go to an emergency department now, and do not drive yourself.
Can an online doctor assess cauda equina syndrome?
Only the first check happens online. Suspected cauda equina syndrome needs an emergency MRI scan in hospital and often an operation, so any warning sign means going to an emergency department straight away, not a video appointment. What a doctor by video can do is go through back pain or sciatica with you, check carefully for the warning signs, explain exactly what to look out for, and send you to hospital at once if any are there. After treatment, the doctor can help with recovery questions such as pain, bladder and bowel symptoms, sex and mood.
How an online consultation helps with cauda equina syndrome
- Warning signs checked first: Numbness around the genitals or bottom, and bladder, bowel and leg changes, are asked about before anything else.
- A clear instruction if you need hospital: If a warning sign is there, the doctor tells you to go to an emergency department now, and not to drive yourself.
- Know what to watch for: With back pain or sciatica and no warning signs, you leave knowing which changes mean going straight to hospital.
- Help after treatment: Pain, bladder and bowel symptoms, sexual problems and low mood after cauda equina syndrome, and the support available.
What the doctor checks in an online back pain consultation
The doctor asks about the warning signs before anything else, because they decide whether you need a hospital now. The doctor asks about:
- Feeling in the saddle area: numbness, tingling or a different feeling around your genitals, your bottom or the inside of your thighs, the parts that would touch a saddle.
- Peeing: difficulty starting, a weaker stream, not feeling the pee pass, or not being able to control it.
- Your bowels: not noticing when you need to poo, or not being able to control it.
- Both legs: sciatica in both legs, or weakness or numbness in both legs that is severe or getting worse.
- Sex: loss of feeling in the genitals, or new problems with erections or ejaculation.
- The back pain itself: when it started, whether it followed lifting or an injury, and any history of back surgery, cancer, a fever or weight loss.
If any warning sign is new for you, the doctor will tell you to go to an emergency department straight away, whatever the time of day.
What is cauda equina syndrome?
The cauda equina is the bundle of nerve roots at the lower end of the spinal cord. These nerves serve the legs, the bladder, the bowel and the genitals, and the feeling in the saddle area. Cauda equina syndrome (CES) happens when they are squeezed. It is rare, affecting about 1 to 3 in 100,000 people a year, but it is a surgical emergency: the longer the nerves are squeezed, the higher the risk of permanent damage.
What causes it?
Most often a large slipped (prolapsed) disc in the lower back pressing on the nerves; the prolapsed disc page explains discs. Narrowing of the lower spinal canal (spinal stenosis), an infection, a tumour such as bone cancer, and a fracture are rarer causes.
Can cauda equina syndrome come and go?
The symptoms usually build up rather than come and go. They can start suddenly or develop slowly over time, which makes them easy to miss. Any warning sign that appears, even if it seems to settle, needs checking in hospital.
What are the symptoms of cauda equina syndrome?
The warning signs affect feeling in the saddle area, the bladder and bowel, sex and both legs. Any one of them, if it is new for you, needs an emergency assessment; you do not need to have them all.
Swipe sideways to compare →
| Warning sign | What you might notice |
|---|---|
| Saddle numbness | Numbness, tingling or a strange feeling around your genitals, your bottom or your inner thighs |
| Bladder changes | Difficulty starting to pee, a weaker stream, not feeling the pee pass, not being able to pee, or leaking |
| Bowel changes | Not noticing when you need to poo, or not being able to control it |
| Both legs | Sciatica in both legs, or weakness or numbness in both legs that is severe or getting worse |
| Sexual problems | Loss of feeling in the genitals, or new problems with erections or ejaculation |
| Back pain | Often, but not always: some people have little or no back pain |
What is the saddle area?
The parts of the body that would touch a saddle when you sit on a bike: the genitals, the area around the back passage, the buttocks and the inner thighs. The nerves to this area come from the cauda equina, so new numbness there is a key warning sign.
Saddle anaesthesia or saddle paraesthesia?
Saddle anaesthesia means a loss of feeling (numbness) in the saddle area. Saddle paraesthesia means an altered feeling there, such as tingling or pins and needles. Both are warning signs.
Incomplete and complete cauda equina syndrome: why timing matters
Doctors describe cauda equina syndrome by how much the nerves have already been affected, because it decides how fast surgery is needed and how much is likely to recover:
Swipe sideways to compare →
| Stage | What it means | What happens next |
|---|---|---|
| Suspected | Warning signs are present, and the scan has not been done yet | An emergency MRI scan, as soon as possible |
| Incomplete (CES-I) | Feeling or control is changing, but you can still control your bladder | Surgery as quickly as possible, to give the best chance of keeping bladder, bowel and sexual function |
| With retention (CES-R) | The bladder no longer empties and can leak without you feeling it, often painlessly | Surgery within 24 hours of the scan; about 70% of people still benefit |
Delays raise the risk of lasting problems with the bladder, bowel and sex, which is why the advice is to go to hospital at the first warning sign rather than waiting to see if it gets worse.
How is cauda equina syndrome diagnosed?
With an emergency MRI scan of the lower back. Under England’s national pathway for suspected cauda equina syndrome, the scan should be done as soon as possible, and within 4 hours of being requested, by day or night.
- The hospital doctor examines your legs, your reflexes and the feeling in the saddle area.
- A bladder scan after you pee may show how much is left in the bladder. More than 200ml makes cauda equina syndrome about 20 times more likely, but a bladder scan alone cannot rule it out: in the national pathway, 60% of people who needed emergency surgery had less than that.
- You may be asked not to eat or drink while you wait, in case you need an operation.
How is cauda equina syndrome treated?
Usually with emergency surgery to take the pressure off the nerves, called decompression, most often by removing the part of the disc that is pressing on them. When the cause is an infection or a tumour, treatment such as antibiotics or radiotherapy is used instead.
What is the success rate of cauda equina surgery?
Earlier treatment gives the best results. Even with retention, about 70% of people benefit from surgery, but some do not regain full bladder, bowel or sexual function, and recovery is gradual, over weeks or months. Without prompt treatment, cauda equina syndrome can lead to permanent weakness of the legs, loss of bladder or bowel control, loss of sexual feeling and long-term pain.
What might the doctor recommend for back pain with possible warning signs?
The first question is always whether there is a warning sign. This is the framework the doctors use:
Swipe sideways to compare →
| What you have | Likely first step | Suitable for online care? | When in-person care is needed |
|---|---|---|---|
| Back pain or sciatica in one leg, no warning signs | Pain relief, staying active, and a clear list of the warning signs | Yes | If a warning sign appears |
| Back pain with a fever, a history of cancer or weight loss you cannot explain | Tests for another serious cause | Yes, to assess | Get medical advice the same day |
| Weakness in one leg or foot that is getting worse | Urgent assessment | Yes, to assess | Prompt examination in person |
| Recovering after surgery for cauda equina syndrome | Help with pain, bladder, bowel and sexual symptoms, mood and the next steps | Partly | Your surgical team, and continence and rehabilitation services |
| Numbness around the genitals or bottom, new bladder or bowel changes, or sciatica or weakness in both legs | Emergency MRI scan | No | Call 112 or go to an emergency department now |
Back pain or sciatica, and not sure which signs matter? A doctor can go through them with you in one consultation.
See available times →Recovery and living with cauda equina syndrome
Recovery after decompression is gradual and can take weeks or months. Some people are left with long-term bladder, bowel or sexual problems, numbness or nerve pain, and support makes a real difference:
- Bladder and bowel: continence services can help with routines, equipment and treatment.
- Nerve pain: a review of your pain relief, and a specialist pain team if it is hard to control.
- Movement: physiotherapy to rebuild strength and confidence in walking.
- Sex and relationships: problems with sexual feeling or function can follow nerve damage, and can be talked through with a doctor.
- Mood: living with these changes is hard, and talking support helps.
Prescription treatment
A prescription is never issued without a consultation. Emergency treatment is given in hospital. After cauda equina syndrome, the doctor may review your pain relief or prescribe for a urinary infection or constipation when it is right for you, in line with your specialist team’s plan. Opioid painkillers such as codeine and tramadol, gabapentin, pregabalin and benzodiazepines are never prescribed online. If the doctor prescribes, use the prescription at a pharmacy near you.
What does not help
Waiting to see whether numbness or bladder changes pass. Driving yourself to hospital with numb or weak legs. Relying on a bladder scan alone. Booking a routine appointment for a warning sign.
Special situations
If you already have sciatica or a slipped disc
Most cauda equina syndrome comes from a slipped disc, so if you have sciatica, learn the warning signs and keep them somewhere you will see them. The sciatica page explains how sciatica is managed.
Travelling in Europe
If a warning sign starts while you are away, call 112: the number works across the EU, free of charge. Carry a list of your medicines. Other holiday health problems are covered on the travel illnesses page.
Children
Mobi Doctor consultations are for adults aged 18 and over. A child who is unwell needs a paediatrician or a local doctor in person, and emergency signs in a child mean 112.
When cauda equina syndrome is assessed online, and when you need in-person care
Assessed online: back pain and sciatica checked for the warning signs, a clear list of what to watch for, and support with pain, bladder, bowel and sexual symptoms and mood after treatment.
In-person care: any suspected cauda equina syndrome, which needs an emergency MRI scan and often surgery, examinations, bladder scans, and rehabilitation.
When to get in-person care
Call 112 or go to an emergency department now for:
- numbness or tingling around or under your genitals, around your bottom or in your inner thighs
- new difficulty starting to pee, being unable to pee, not feeling your pee, or not being able to control when you pee
- not noticing when you need to poo, or not being able to control your bowels
- sciatica in both legs, or weakness or numbness in both legs that is severe or getting worse
- new loss of feeling in your genitals, or new problems with erections or ejaculation
Get medical advice the same day for:
- weakness in one leg or foot that is getting worse
- back pain with a fever or feeling generally unwell
- new back pain with a history of cancer, or weight loss you cannot explain
How Mobi Doctor works
- Book a time that suits you: daily 7am–11pm CET. You can see a doctor over video, usually within 15 minutes. No subscription, and the exact price is shown before you pay.
- Speak to a licensed doctor about your back: describe the pain and where it spreads, and say straight away if anything has changed in the saddle area, your bladder or your bowels.
- Leave with a plan: what to do, what to take and for how long, and which signs mean you should be seen in person. If the doctor prescribes, use the prescription at a pharmacy near you.
No sign-up needed
If you have any warning sign listed on this page, call 112 now. Otherwise, tick every symptom you have to see each condition page that mentions it. It finds the right page, not a diagnosis: a doctor gives you that on a video call.
Tap the body — an area or a point — to browse symptoms anywhere
Similar symptoms, different condition? Sciatica can start the same way. Compare them, or look up any other symptom in the full symptom checker.
Frequently asked questions about cauda equina syndrome
What is cauda equina syndrome?
A rare emergency in which the bundle of nerve roots at the base of the spine, the cauda equina, is squeezed, most often by a large slipped disc. It can affect the bladder, bowel, sexual function and legs, and needs emergency treatment.
What are the first signs of cauda equina syndrome?
The first signs of cauda equina syndrome are numbness or tingling around the genitals, bottom or inner thighs, new difficulty peeing or controlling your bladder or bowels, and sciatica or weakness in both legs. Any one of these needs an emergency assessment.
What is the saddle area?
The parts of the body that would touch a saddle: the genitals, the area around the back passage, the buttocks and the inner thighs. New numbness there is a key warning sign of cauda equina syndrome.
When should I go to hospital with back pain?
Straight away, by calling 112 or going to an emergency department, if back pain or sciatica comes with the warning signs of cauda equina syndrome: numbness in the saddle area, new bladder or bowel problems, sciatica in both legs, or weakness or numbness in both legs.
Can cauda equina syndrome come and go?
The symptoms of cauda equina syndrome usually build up rather than come and go, and they can develop slowly, which makes them easy to miss. Any warning sign, even one that seems to settle, needs checking in hospital.
What causes cauda equina syndrome?
Cauda equina syndrome is most often caused by a large slipped disc in the lower back. Narrowing of the spinal canal, an infection, a tumour and a fracture are rarer causes.
Can cauda equina syndrome be prevented?
Not reliably, because it usually comes from a large slipped disc that cannot be predicted, but the damage can be: knowing the warning signs and acting on them within hours is what protects the nerves. Looking after your back lowers the chance of a disc prolapse in the first place: lift with bent knees and a straight back, keep active and strong, keep to a healthy weight, and do not smoke, which weakens discs. Anyone with sciatica should know the cauda equina warning signs.
How rare is cauda equina syndrome?
Cauda equina syndrome affects about 1 to 3 in 100,000 people a year. It is rare, but the warning signs matter because early treatment protects the nerves.
How is cauda equina syndrome diagnosed?
Cauda equina syndrome is diagnosed with an emergency MRI scan of the lower back, together with an examination. England’s national pathway asks for the scan within 4 hours of the request, by day or night.
What is the difference between complete and incomplete cauda equina syndrome?
In incomplete cauda equina syndrome, feeling or control is changing but you can still control your bladder. In the complete form, with retention, the bladder no longer empties and can leak without you feeling it. Recovery is better when treatment starts earlier.
What is the treatment for cauda equina syndrome?
Cauda equina syndrome is usually treated with emergency surgery to take the pressure off the nerves, most often by removing the part of the disc pressing on them. Infections and tumours are treated with antibiotics or radiotherapy.
What is the success rate of cauda equina surgery?
Results of cauda equina surgery are best when it is done early. Even with retention, about 70% of people benefit, but some are left with bladder, bowel or sexual problems, and recovery can take weeks or months.
Can an online doctor assess cauda equina syndrome?
Only the first check. A doctor by video can go through back pain and sciatica for the warning signs, but suspected cauda equina syndrome needs an emergency department and an MRI scan straight away.
- Sciatica, NHS, National Health Service (UK), reviewed 3 December 2024.
- National suspected cauda equina syndrome (CES) pathway, Getting It Right First Time (GIRFT), NHS England, February 2023.
- Cauda equina syndrome, OrthoInfo, American Academy of Orthopaedic Surgeons, accessed 15 October 2026.
- Cauda equina syndrome, Patient.info, Dr Colin Tidy, updated 20 June 2024.
This page is for information only and is not a substitute for a medical consultation. Guideline links are provided for transparency; treatment decisions are made with your doctor.
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