Cauda equina syndrome (CES) is a rare but serious condition caused by compression of the nerves at the lower end of the spinal canal. It can develop suddenly or gradually, and the earliest changes are not always immediately obvious. 

As the condition is a medical emergency, recognising the early symptoms of cauda equina syndrome is important because delays in diagnosis and treatment can lead to lasting nerve damage. In this guide, we explain the first signs to look out for, how symptoms can develop over time, the red flags that require immediate medical attention, and how to make a cauda equina syndrome claim if you are concerned that signs of CES were missed.

What early bladder symptoms can cauda equina syndrome cause?

Bladder changes are among the most important cauda equina symptoms to recognise because nerve compression can interfere with the signals controlling bladder function.

Early urinary symptoms can include increasing difficulty starting to urinate, reduced awareness of the need to pass urine, altered urinary flow or difficulty knowing whether the bladder is full or empty. Some people develop urinary retention, while others experience leaking or a loss of bladder control.

A new inability to urinate or control when you urinate is a red flag symptom requiring immediate medical assessment.

What bowel changes can be an early sign of cauda equina syndrome?

Cauda equina syndrome can cause bowel dysfunction because the compressed nerves also help control sensation around the bowel and back passage.

Possible early symptoms include reduced awareness that you need a bowel movement, altered sensation when opening your bowels, difficulty controlling your bowel or reduced feeling when wiping with toilet paper. New loss of bowel sensation or control is a red flag, especially alongside other symptoms of cauda equina.

What is saddle numbness?

Saddle numbness, or saddle anaesthesia, is a common early symptom of cauda equina syndrome. It means reduced or altered sensation in the areas that would touch a saddle when sitting. This includes the genitals, inner thighs, buttocks and area around the back passage.

It does not always begin as complete numbness. Early symptoms may include tingling, reduced sensitivity or simply a feeling that the skin is different from normal. Some people first notice a change when washing, using toilet paper or during sexual activity.

What leg symptoms can occur in early cauda equina syndrome?

Symptoms of cauda equina can include leg pain, numbness, pins and needles, muscle weakness or altered sensation in the lower limbs. They may affect one or both legs.

Sciatica on both sides, or severe or worsening weakness or numbness in both legs, is particularly concerning. Leg weakness can also cause increasing difficulty walking or standing.

You can still be able to walk in the early stages of cauda equina syndrome. Being mobile does not rule out CES if other red flag symptoms are present.

Can cauda equina syndrome affect sexual function?

Yes. The cauda equina nerves contribute to genital sensation and sexual function. Compression can therefore cause reduced genital sensation, changes during sexual intercourse, erection problems or changes in ejaculation.

Doctors should consider new sexual-function changes alongside bladder, bowel, saddle-area and lower-limb symptoms when assessing possible cauda equina syndrome.

How do cauda equina syndrome symptoms begin and progress?

Cauda equina syndrome does not always follow one pattern. Symptoms can have a rapid onset or develop more gradually as pressure on the nerve roots increases.

Can cauda equina symptoms start suddenly?

Some people experience a rapid onset of severe back or leg pain followed by neurological changes such as numbness, leg weakness, urinary symptoms or saddle anaesthesia. A large herniated disc is one possible cause of sudden nerve compression.

Can cauda equina symptoms develop gradually?

In other cases, symptoms build over time where compression develops progressively, for example because of disc herniation or spinal stenosis. A person may first notice intermittent numbness, altered bladder sensation or increasing leg weakness before more obvious red flags appear.

Can early cauda equina symptoms come and go?

Some early symptoms may fluctuate. This does not mean the underlying problem is harmless. New bladder, bowel, saddle-area, sexual-function or neurological leg symptoms still require urgent assessment where cauda equina syndrome is a possibility.

Can cauda equina syndrome be mild at first?

Early symptoms of cauda equina syndrome can sometimes be subtle or incomplete. A person may initially notice only a change in sensation, urinary function or leg strength rather than the full group of recognised red flags.

However, possible CES should not be treated as a minor condition. Symptoms can progress, and untreated nerve compression can cause permanent damage.

How are early cauda equina symptoms different from back pain or sciatica?

Back pain and sciatica are common and do not usually mean a person has cauda equina syndrome. The concern is when back or leg pain appears alongside neurological red flags involving both legs, the saddle area, bladder or bowel function.

This table is not a diagnostic tool. If you experience symptoms that may indicate cauda equina syndrome, follow NHS emergency advice and seek immediate medical attention.

What are the red flags for cauda equina syndrome?

The main red flag symptoms include:

• Sciatica on both sides of the back, hips and legs.
• Severe or worsening weakness or numbness in both legs.
• Numbness around or under the genitals, or around the anus.
• New difficulty starting to urinate, inability to urinate or the loss of bladder control.
• Not noticing when you need a bowel movement or being unable to control your bowels.

The NHS advises going to A&E or calling 999 if these symptoms occur. Do not drive yourself to A&E; ask someone to take you or call an ambulance.

Read more about the red flag symptoms of cauda equina syndrome.

How do doctors check for cauda equina syndrome?

Doctors assess the pattern of symptoms and carry out a neurological examination when cauda equina syndrome is suspected. This can include checking leg strength, sensation and reflexes, alongside bladder, bowel and sexual function.

Magnetic resonance imaging (MRI) is used to identify whether the cauda equina nerve roots are compressed and what is causing the compression. Read more in JMW's guide to common cauda equina syndrome test methods.

How is cauda equina syndrome treated?

Where imaging confirms cauda equina nerve compression, urgent spinal decompression surgery may be required to relieve pressure on the nerves. The exact procedure depends on the cause - a herniated disc or spinal stenosis can often be addressed through surgery, for example.

The aim is to reduce the risk of permanent damage to bladder, bowel, sexual and lower-limb function. The NHS explains lumbar decompression surgery and why it is used for some conditions involving compressed nerves in the lower spine.

It is important to recognise that surgery needs to be performed quickly for the best chances of recovery, which is why it is vital for the condition to be diagnosed promptly.

Why is recognising cauda equina syndrome early important?

Recognising cauda equina syndrome symptoms early is very important because prolonged nerve compression can cause lasting neurological damage affecting bladder control, bowel control, sexual function, sensation, leg strength and mobility.

Prompt recognition allows doctors to investigate whether CES is present and decide what treatment is required. For broader information, read JMW's guide to what cauda equina syndrome is.

What if the early symptoms of cauda equina syndrome were missed?

A poor outcome after cauda equina syndrome does not automatically mean medical negligence occurred. However, there may be grounds to investigate a medical negligence claim where care provided by a GP, hospital doctor, nurse, surgeon or another relevant clinician fell below a reasonable standard and caused or contributed to additional injury.

Examples can include:

• A GP or hospital doctor failing to respond appropriately to reported red flag symptoms.
• An urgent hospital or spinal referral not being arranged when it should have been.
• An avoidable delay in arranging an MRI scan where CES was suspected.
• Evidence of nerve compression not being acted on appropriately.
• An avoidable delay in treatment causing or contributing to lasting bladder, bowel, sexual-function or mobility problems.

JMW's specialist solicitors investigate the medical records, sequence of symptoms and treatment, and the impact of any avoidable delay. Where appropriate, we instruct independent medical experts to assess whether the care met a reasonable standard and whether any failings caused or contributed to the outcome.