When Is Back Pain Serious Enough to See Someone?
Most back pain improves within a few weeks. It becomes serious when it is accompanied by red flag symptoms such as numbness, leg weakness, or changes to bladder or bowel control. Pain that persists beyond six weeks, follows trauma, or wakes you at night also warrants professional assessment to rule out an underlying cause.
Key takeaways
- Sudden numbness, weakness or loss of bladder or bowel control needs urgent medical attention.
- Back pain lasting more than six weeks, or pain after an injury, should be investigated.
- Fever, unexplained weight loss or a history of cancer alongside back pain are red flags.
- Standing imaging can reveal 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 that suggest back pain may have a serious underlying cause, rather than simple muscle strain. Doctors and physiotherapists are trained to check for these during an assessment. If any of the following apply to you, it is important to seek advice promptly.
Especially in the groin, buttocks or legs. This may indicate nerve involvement such as nerve root compression.
Difficulty lifting a foot, climbing stairs or feeling that a leg is giving way can signal nerve pressure.
Any new difficulty controlling your bladder or bowel is a medical emergency. Go to A&E immediately.
Pain that is constant, unrelated to movement, and disturbs sleep can sometimes point to an infection or other condition that needs investigation.
These general symptoms alongside back pain may indicate infection, inflammation, or something that needs urgent blood tests and imaging.
If you have had cancer before and develop new, persistent back pain, speak to your doctor without delay.
When should I go to A&E for back pain?
You should go to A&E or call 999 if your back pain comes with any of the following, because they may indicate a condition called cauda equina syndrome, which needs emergency treatment.
Seek urgent medical attention (GP, 111, or A&E) if you have:
- Numbness around your genitals, buttocks or inner thighs (sometimes called saddle numbness).
- Loss of bladder or bowel control, or inability to urinate.
- Sudden severe weakness in both legs.
- These symptoms developing rapidly alongside back pain.
Do not wait. These symptoms require emergency assessment, not a scan booking.
If your situation does not match the above but you are unsure, calling NHS 111 is a good first step. They can advise you on whether you need to be seen urgently.
What if my back pain will not go away but is not an emergency?
Back pain that lingers for more than six weeks without improving is considered persistent. It is not usually dangerous, but it does deserve proper investigation. Without a clear diagnosis, you can end up going round in circles, trying treatments that do not address the actual cause.
There are several situations where seeing someone sooner rather than later makes sense:
- Pain that started after a fall, accident or injury.
- Pain that is gradually getting worse rather than 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 experiencing a new type of back pain.
Knowing when to see a specialist can help you avoid months of uncertainty. A targeted assessment can find what is driving the pain and point you toward the right next step.
How does standing imaging help find the cause of back pain?
Standing imaging captures your skeleton under real load, in the position where your pain actually happens. This is important because lying-down scans, such as a standard X-ray, CT or MRI, relax the muscles and can mask 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. These compensation patterns can mean the place where you feel pain is not where the problem started. A full standing image of the whole body can reveal these links in a way that a single-area scan 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, in the position where your symptoms appear.
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 appropriate for your situation, we will tell you.
What helps when back pain is not improving?
The most helpful first step is getting a clear understanding of what is causing the pain. Without that, treatment is guesswork. A thorough assessment, whether from your GP, a physiotherapist, or a specialist, should look at your symptoms, your history, and how your body moves and loads.
If standard investigations have not given you answers, a whole-body standing assessment can add a layer of information that single-area scans miss. It does not replace your doctor or physiotherapist. It gives them, and you, a clearer map of what is going on structurally.
ScanAlign provides diagnostic imaging only. We do not offer treatment. What we provide is the detailed alignment picture 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 movement changes, and improves 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 improve with rest, or pain that wakes you at night should be discussed with your GP promptly. These are considered red flag symptoms.
Numbness in the legs alongside back pain often suggests a nerve is being compressed or irritated, sometimes at the spinal level. This needs clinical assessment. If the numbness is in the groin, buttocks or inner thighs, or you have bladder or bowel changes, seek urgent medical attention immediately.
Go to A&E 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 GP is the right starting point. You can also call NHS 111 if you are unsure.
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 appropriate 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 removed and your muscles relax. Alignment problems, pelvic tilts and leg-length differences that cause pain when you are standing and moving may not be visible. A standing scan captures your skeleton under real load, showing how your body actually functions.
Pricing information is available on our FAQs page. You can also ask about costs during your free video consultation.
Yes. Because your body is a connected chain, an alignment issue at one level often causes compensation elsewhere. A tilted pelvis, for example, can lead to hip pain, knee strain or mid-back stiffness. That is why whole-body imaging can be valuable when single-area scans 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.