Should You See a Doctor About This Pain? The Signs Not to Wait On
BaroSit · 2026-07-30 · 📝 블로그
When your back aches or your leg tingles, it is genuinely hard to tell whether this is ordinary stiffness or something worth getting checked.
Search for an answer and you will find no shortage of "warning signs" lists. I set out to put together a clear one myself.
But something had to come first. It turns out researchers have already asked how reliable those lists actually are.
① Those warning-sign lists are less tested than you would think
One review gathered the red flags that clinical guidelines recommend for back pain and examined them one by one. Fourteen studies, fifty-three separate signs.
The findings were not what I expected. Many of them barely shift the probability of anything at all, and some had never been tested for accuracy in the first place.
The authors went as far as to conclude that many current guidelines need revising.
This is worth stating carefully. It does not mean warning signs can be ignored. Some of them clearly do carry information, and the problem is that the rest have been treated as though they carry the same weight.
② One sign rarely settles it. Overlap does.
In that same review, the signs that genuinely raised the likelihood of a fracture were these, in order of how much they mattered.
▸ Bruising or grazing over the spot where you fell or took a knock
▸ Long-term steroid use
▸ Serious trauma, such as a car accident
▸ Older age
For cancer, the strongest single item was a previous history of cancer.
And the likelihood climbed considerably higher when several of these appeared together rather than one on its own.
There is a reason I have not reproduced the actual probability figures from that review. Those numbers depend on the setting a patient came through, so they do not transfer to your situation. The same paper notes that among people bringing back pain to primary care, spinal fracture accounts for somewhere between 1 and 4 per cent.
So what to take from this is not a number. It is the ordering, and the overlap.
One more boundary: this review looked only at fracture and cancer. The nerve symptoms and the clot below were not part of it.
③ Some situations are worth acting on even when the odds are low
This is the part of the article that matters most.
There is a condition called cauda equina syndrome, in which the bundle of nerves at the base of the spine is compressed. Without timely treatment it can leave permanent damage to bladder and bowel function, or to the strength in your legs.
By the numbers it is not common. One study put it at 0.08 per cent of people bringing back pain to primary care, and even among those investigated on suspicion of it, only 19 per cent turned out to have it.
Eight out of ten people who get scanned do not have it, in other words. Numbers like that usually nudge you toward "so mostly a wasted trip."
Here you have to read them the other way round. The odds are low, but what is lost if you miss it cannot be recovered. That combination, low probability and irreversible loss, is exactly where going without certainty is the right call.
The national care pathway published by NHS England says something similar. No single symptom or sign confirms the condition, and a negative test does not rule it out when the symptoms are there.
④ So which signs should not wait
These are the symptoms that document flags for emergency assessment, alongside back or leg pain, when they have appeared recently.
▸ Difficulty starting to urinate, or a dulled sense of urine passing
▸ Altered sensation around the perineum or genitals, the area that meets a saddle when you sit
▸ Weakness in both legs, or weakness that keeps getting worse
▸ Losing the sense that the bowel is full
▸ A change in sexual function
Pain that had been shooting down one leg and suddenly spreads to both is also treated as a warning.
This is not a checklist so much as a threshold. You are not counting how many apply. If even one of them fits, that is the day to get it looked at.
For those of us who sit for a living there is one more: a leg that swells and hurts on one side only.
Both legs puffing up after a long day at a desk is common enough. One leg doing it is a different matter, and other causes are meant to be ruled out first. UK guidance says as much, that a swollen or painful leg calls for history and examination to exclude other explanations.
The earlier items are worth not brushing aside either. Severe pain after a fall or a collision, long-term steroid use, a history of cancer.
⑤ And otherwise
If none of this describes you, most ordinary stiffness is the kind you can hand over to time and movement.
It helps to hold the standard this simply.
▸ Any one of the nerve symptoms above — do not wait
▸ Several warning signs overlapping — do not wait
▸ Pain and nothing else — watch it, and watch whether it is heading the right way
One last thing. If you were told the scans showed nothing but the symptoms have stayed the same or got worse, that is a situation you can go back about.
That is precisely what the care pathway asks clinicians to keep in mind. A negative test does not erase a symptom.
So the question this article was really trying to answer was not "what is dangerous."
It was whether this can wait.
Sources
• Downie et al., 2013 · BMJ 347:f7095 — Diagnostic accuracy of 53 red flags across 14 studies (8 primary care, 2 secondary, 4 tertiary). For fracture, the highest post-test probabilities were contusion or abrasion, prolonged corticosteroid use, severe trauma and older age, in that order, and probability was higher when multiple red flags were present. For malignancy, history of cancer ranked highest. Post-test probability depends on the pre-test probability of the care setting, and the authors could not pool the data because of heterogeneity. Only 5 studies evaluated combinations. Fracture and malignancy only
• Hoeritzauer et al., 2020 · J Neurosurg Spine 32(6):832–841 — 26 studies. Cauda equina syndrome occurred in 0.08% of those with low back pain in primary care (1 study) and 0.27% in secondary care, and 19% of adults investigated for suspected CES had it. The authors note limits in the data: all 18 studies single-centre, 17 from the UK, largely retrospective
• NHS England GIRFT, National Suspected Cauda Equina Syndrome Pathway, February 2023 — Symptoms warranting emergency MRI referral. "No single symptom or sign is pathognomonic", "an MRI scan on its own cannot diagnose CES", and negative physical tests do not rule out CES if positive subjective symptoms are present
• NICE guideline NG158 (2020, updated 2023) 1.1.1 — For a swollen or painful leg, assess medical history and examine to exclude other causes
• NICE guideline NG59 (2016, updated July 2026) 1.1.1 — Consider alternative diagnoses when symptoms are new or changed, and refer if serious underlying pathology is suspected
This article is general health information. It is not medical advice, and it is not a tool for diagnosing yourself. The symptom lists here come from UK health service documents and published research, and judging your own situation is a job for a clinician. When you cannot tell, being seen is the safer side to err on.