When Is Back Pain Serious Enough to See a Doctor?
Most back pain gets better within a few weeks. It becomes serious when it comes with red flag symptoms, such as numbness, leg weakness, or changes in bladder or bowel control. Pain that lasts more than six weeks, starts after an injury or accident, or wakes you at night also needs a professional assessment. This helps rule out an underlying cause.
Key takeaways
- Sudden numbness, weakness or loss of bladder or bowel control needs urgent medical attention.
- Back pain that lasts more than six weeks, or pain after an injury, should be investigated.
- Fever, unexplained weight loss or a history of cancer together with back pain are red flags.
- Standing imaging can show alignment problems that lying-down scans may miss.
- Most back pain is not dangerous, but getting the right diagnosis early helps you get the right care.
What are the red flags for back pain?
Red flags are specific warning signs. They suggest back pain may have a serious underlying cause, not just a simple muscle strain. Doctors and physiotherapists are trained to check for these during an assessment. If any of the signs below apply to you, it is important to get advice promptly.
Especially in the groin, buttocks or legs. This may point to a nerve problem such as nerve root compression.
Trouble lifting a foot, climbing stairs or a feeling that a leg is giving way can be a sign of pressure on a nerve.
Any new difficulty controlling your bladder or bowel is a medical emergency. Go to the emergency department straight away.
Pain that is constant, not linked to movement, and disturbs your sleep can sometimes point to an infection or another condition that needs investigation.
These general symptoms together with back pain may point to infection, inflammation, or something that needs urgent blood tests and imaging.
If you have had cancer before and now have new back pain that does not go away, speak to your doctor without delay.
When should I go to the emergency department for back pain?
Go to the emergency department or call your local emergency number if your back pain comes with any of the signs below. They may point to a condition called cauda equina syndrome, which needs emergency treatment.
Get urgent medical attention (your doctor or the emergency department) if you have:
- Numbness around your genitals, buttocks or inner thighs (sometimes called saddle numbness).
- Loss of bladder or bowel control, or being unable to pass urine.
- Sudden severe weakness in both legs.
- Any of these symptoms coming on quickly together with back pain.
Do not wait. These symptoms need emergency assessment, not a scan booking.
If your situation does not match the list above but you are unsure, contacting your doctor is a good first step. They can tell you whether you need to be seen urgently.
What if my back pain will not go away but is not an emergency?
Back pain that lasts more than six weeks without getting better is called persistent. It is not usually dangerous, but it does deserve a proper investigation. Without a clear diagnosis, you can end up going round in circles, trying treatments that do not deal with the actual cause.
In some situations it makes sense to see someone sooner rather than later:
- Pain that started after a fall, accident or injury.
- Pain that is slowly getting worse, not better.
- Stiffness or pain that limits your daily activities, work or sleep.
- Pain that spreads into your legs, especially below the knee.
- You are over 50 and have a new type of back pain.
Knowing when to see a specialist can help you avoid months of uncertainty. A focused assessment can find what is driving the pain and point you to the right next step.
How does standing imaging help find the cause of back pain?
Standing imaging captures your skeleton under real load, upright and carrying your body weight. This matters because lying-down scans, such as a standard X-ray, CT or MRI, relax the muscles. They can hide alignment problems that only appear when you are upright and weight-bearing.
Your body works as a connected chain from your feet to your head. If your pelvis is slightly tilted, your spine compensates. If one leg carries more weight, your back muscles adjust. Because of these patterns, the place where you feel pain may not be where the problem started. A full standing image of the whole body can show these links in a way that a scan of one area cannot.
EOS is a low-dose imaging system that takes a full-length standing image of your skeleton, using about 90% less radiation than a standard X-ray, around ten times less. The result is a detailed picture of your alignment from head to feet, all in one scan, upright and under load.
You can read more about how this works on our back pain clinic page.
A note on MRI. EOS shows bones, joints and alignment. For soft tissue, discs or nerves, MRI is usually the better tool. In many cases, both types of imaging together give the fullest picture. If MRI is more suitable for your situation, we will tell you.
What helps when back pain is not getting better?
The most helpful first step is a clear understanding of what is causing the pain. Without that, treatment is guesswork. A thorough assessment, whether from your doctor, a physiotherapist or a specialist, should look at your symptoms, your history, and how your body moves and carries load.
If standard tests have not given you answers, a whole-body standing assessment can add information that scans of one area miss. It does not replace your doctor or physiotherapist. It gives them, and you, a clearer map of what is going on in your body's structure.
Before you start a treatment, or change the one you are on, it is worth getting a detailed diagnosis. Knowing whether the cause sits in your pelvis, your legs or your spine changes what will actually help.
ScanAlign provides diagnostic imaging only. We do not offer treatment. What we provide is a detailed picture of your alignment that helps your treating clinician make better decisions about your care.
Not sure whether imaging is the right next step for your back pain? You can check whether an assessment is right for you with a free video consultation. There is no obligation and no pressure.
Book a free video consultationFrequently asked questions about serious back pain
Muscular back pain usually follows a strain, feels better with rest and changes in movement, and gets better within a few weeks. Pain that is constant, wakes you at night, spreads into your legs, or comes with numbness or weakness may point to a structural or nerve-related cause and should be assessed.
It is common, but not something to ignore. Most simple back pain settles within four to six weeks. If yours has not, it is worth seeing a professional to understand why. Persistent pain does not always mean something serious, but it does mean the cause may need investigating.
In rare cases, yes. Back pain with unexplained weight loss, a history of cancer, pain that does not get better with rest, or pain that wakes you at night should be discussed with your doctor promptly. These are considered red flag symptoms.
Numbness in the legs together with back pain often suggests a nerve is being pressed or irritated, sometimes at the level of the spine. This needs a clinical assessment. If the numbness is in the groin, buttocks or inner thighs, or you have bladder or bowel changes, get urgent medical attention straight away.
Go to the emergency department if you have sudden numbness in the saddle area, loss of bladder or bowel control, or sudden severe weakness in both legs. For other back pain concerns, your doctor is the right place to start. If you are unsure, you can also contact your doctor for advice.
No referral is needed. ScanAlign is a private, self-pay service. You can book a free video consultation directly, and a specialist radiographer will discuss whether an assessment is suitable for you.
Yes. EOS uses about 90% less radiation than a standard X-ray, around ten times less. It is designed for standing, whole-body imaging and is widely used in orthopaedic centres around the world.
When you lie down, gravity is taken away and your muscles relax. Alignment problems, pelvic tilts and differences in leg length that cause pain through upright alignment and load may not be visible. A standing scan captures your skeleton under real load, showing how your body actually works.
The price for patients travelling from abroad is confirmed during your free video consultation.
Yes. Because your body is a connected chain, an alignment problem at one level often causes compensation somewhere else. A tilted pelvis, for example, can lead to hip pain, knee strain or stiffness in the middle of the back. That is why whole-body imaging can be valuable when scans of one area have not given clear answers.
Still wondering whether your back pain needs investigating?
A short video call with a specialist radiographer can help you understand whether a standing alignment assessment is the right next step. No referral needed, no obligation.
Book a free video consultationWritten by Abbas Dhami (Specialist Diagnostic Radiographer)
Sources
- NHS. "Back pain: When to get medical help." nhs.uk, 2023.
- Greenhalgh, S. and Selfe, J. "Red Flags: A Clinically Useful Guide to Identifying Serious Pathology of the Spine." Churchill Livingstone/Elsevier, 2006.
- Illés, T. and Somoskeöy, S. "The EOS imaging system and its uses in daily orthopaedic practice." International Orthopaedics, 36(7), 2012, pp. 1405-1411.
This page is general information and not a diagnosis.
ScanAlign is the trading name of CoreMed Solutions Ltd and operates under The Harley Street Hospital's CQC licence.