We have all been there. You bend over to pick up a heavy box, twist awkwardly to reach a falling object, or simply sleep in a funny position, and boom, your back seizes up.
Back pain is incredibly common. In fact, it is one of the leading reasons people visit the doctor or miss work worldwide [1]. The good news is that the vast majority of back pain is mechanical, meaning it is caused by a muscle or ligament strain. A standard strain usually peaks in the first few days, gradually fades, and completely resolves within a few weeks with a little rest, ice, and gentle movement.
But sometimes, back pain is a warning sign of a more serious underlying condition, such as a herniated disc, spinal stenosis, an infection, or even a fracture. In the medical world, these are called “red flags.”
How can you tell the difference between a standard pulled muscle and something that requires immediate medical attention? Here are 7 signs your back pain is not just a strain.
1. Pain Radiating Down Your Leg (Sciatica)
A standard muscle strain is usually localized. If you have a strain in your lower back, the pain stays in your lower back. However, if you feel pain that starts in your back and shoots down through your buttock and into your leg, often traveling past your knee and into your calf or foot, this is a sign of nerve involvement, commonly known as sciatica [2]. This usually happens when a spinal disc bulges or herniates and presses directly on the sciatic nerve. Nerve pain is often described as burning, electric, or shooting, and it is very different from a dull, aching muscle pull.
2. Numbness or Tingling in Your Groin or Legs
Muscle strains hurt, but they do not usually change how your skin feels. If your back pain is accompanied by numbness, “pins and needles,” or a loss of sensation in your legs, feet, or groin area, a nerve is being pinched or damaged [3].
Pay special attention to numbness in the inner thighs or groin (often called “saddle anesthesia”). This is a highly specific red flag that indicates compression on the lower spinal nerves, which requires urgent evaluation.
3. Loss of Bowel or Bladder Control
This is an absolute medical emergency. If you experience back pain alongside the sudden inability to control your urine or bowels, or if you experience numbness in the area that would touch a bicycle seat (your saddle region), you need to go to the emergency room immediately [4].
This combination of symptoms points to a rare but serious condition called Cauda Equina Syndrome. The cauda equina is a bundle of nerves at the very bottom of your spinal cord. If these nerves are severely compressed by a massive herniated disc or trauma, they can die off, leading to permanent paralysis and incontinence if not surgically relieved right away.
4. Weakness in Your Legs or Feet
It is normal to avoid putting weight on a painful leg because it hurts to do so. However, true neurological weakness is different. If you physically cannot lift your foot up when you walk (a condition called “foot drop”), or if your legs give out on you without warning, a nerve signal is being blocked [2].
If your muscles simply refuse to work properly alongside your back pain, do not wait to see if it gets better. This requires immediate medical attention for diagnosis and treatment.
5. Pain That Wakes You Up at Night
A typical muscle strain will usually ache when you move, but it generally subsides when you lie flat and rest. Nighttime back pain is a major red flag [5].
If your back pain is severe enough to consistently wake you out of a deep sleep, or if the pain is unrelenting, no matter what position you lie in, it needs to be investigated. While it could be a severe spinal issue, doctors also look for nighttime pain as a potential warning sign of spinal tumors or spinal infections, as these types of pain do not respect rest.
6. Accompanying Fever or Unexplained Weight Loss
Your back does not exist in a vacuum; it is part of your whole body. If your back pain is accompanied by a fever, chills, or recent unexplained weight loss, your spine might be fighting an infection [6].
Spinal infections (like vertebral osteomyelitis or discitis) can occur if bacteria travel through the bloodstream and settle in the spine. This causes deep, agonizing pain that does not respond to over-the-counter medications. If you have a fever with back pain, you should see a doctor the same day to get bloodwork and potentially an MRI.
7. It Started After a Major Trauma (Or You Have Osteoporosis)
If you were in a car accident, took a severe fall, or suffered a sports injury and now have back pain, you should always be evaluated by an orthopedic specialist to rule out a spinal fracture [7].
Furthermore, if you have been diagnosed with osteoporosis (a condition that weakens bones), even a minor stumble or a sudden, forceful cough can cause a vertebral compression fracture. Unlike a muscle strain, a fracture causes a very sharp, pinpoint pain that usually gets much worse when you stand up or try to walk, and feels slightly better when you lie completely flat.
When to See a Specialist for Back Pain
If your back pain started after heavy lifting, is localized to one side of your lower back, and feels like a tight, dull ache that improves with ibuprofen and a heating pad, it is highly likely just a strain. Give it a few days of gentle movement and rest.
However, if you check any of the 7 boxes above, especially numbness, weakness, bowel/bladder issues, or fever, do not try to “tough it out.” Early intervention for serious spinal issues is the best way to prevent permanent damage and get you back to living pain-free. Come see us at The Orthopedic and Sports Medicine Institute if you are concerned about persistent pain or suspect an injury. Our goal at the Orthopedic and Sports Medicine Institute (OSMI) is to provide our patients with quality, cutting-edge orthopedic treatments, both surgical and non-surgical. If you would like to book an appointment, please submit an online appointment request or contact our office. We have clinic locations in Fort Worth, Mansfield, and Decatur.
References
[1] Hartvigsen, J., Hancock, M. J., Kongsted, A., et al. (2018). What low back pain is and why we need to pay attention. The Lancet, 391(10137), 2356-2367.
[2] American Academy of Orthopaedic Surgeons (AAOS). (2021). Herniated Disc in the Lower Back. OrthoInfo. Retrieved from https://orthoinfo.aaos.org/en/diseases–conditions/herniated-disk-in-the-lower-back
[3] Deyo, R. A., & Dworkin, S. F. (2014). Low back pain and sciatica: A review. JAMA, 312(7), 683-691.
[4] National Health Service (NHS). (2023). Cauda Equina Syndrome. NHS UK. Retrieved from https://www.nhs.uk/conditions/cauda-equina-syndrome/
[5] Finckh, A., Businger, A., Felder, M., et al. (2022). Red flags for serious spinal pathology in patients presenting with low back pain: A systematic review. European Spine Journal, 31(5), 1134-1144.
[6] Yang K, Zha Y, Chen C, Lu S, Jiang X. The clinical characteristics and outcomes of anaerobic spondylodiscitis: a retrospective observational study. BMC Infect Dis. 2025 Dec 23;26(1):156. doi: 10.1186/s12879-025-12445-6
[7] Downie, A., Williams, C. M., Henschke, N., et al. (2013). Red flags to screen for vertebral fracture in patients presenting with low-back pain. Cochrane Database of Systematic Reviews.
