Back Pain With Fever: Spinal Infection Warning Signs

A few weeks ago you had a bad urinary tract infection. It cleared up, more or less. Now your low back aches all the time. Lying down doesn't help, the pain wakes you at night, and you've felt hot and shivery on and off. You assume you slept funny.

Most back pain really is mechanical: sore muscles, joints and discs that settle with time and movement. But back pain that comes with fever, chills or feeling generally unwell is different. Rarely, it's a sign of an infection in the spine, and that needs a doctor quickly.

What is a spinal infection?

A spinal infection happens when bacteria (or, less often, other germs like tuberculosis) settle in the spine. There are a few types:

• Discitis: infection of a disc between two vertebrae
• Vertebral osteomyelitis: infection of the bones of the spine, often together with discitis
• Spinal epidural abscess: a pocket of infection next to the spinal cord or nerves, which can press on them

Germs often reach the spine through the bloodstream from an infection somewhere else in the body, or after spinal surgery or a procedure. Spinal infections are rare, about 0.2 to 2.4 cases per 100,000 people a year in Western countries, but rates are rising, partly because the population is getting older.

Why it's easy to miss

Many people picture spinal infection as back pain plus a high fever plus nerve problems. In reality, that full picture is uncommon:

• The international red flags framework for physiotherapists notes that fever is absent in about half of people with a spinal infection.
• In a 2025 study of 457 people with a spinal epidural abscess, only 10% had the classic trio of fever, back pain and nerve problems. Over 90% had back or neck pain or tenderness.
• In that same study, 71% had at least one medical visit possibly related to the abscess in the 30 days before they were diagnosed.

In other words, early on it can look a lot like ordinary back pain. That's why the bigger picture matters.

Warning signs to know

Get checked if you have back or neck pain along with any of these:

• Fever, chills, sweats or just feeling unwell
• Pain that is constant and getting steadily worse, and doesn't ease with rest or changing position
• Pain that wakes you at night
• A recent infection (for example, urinary, skin, dental or a bloodstream infection) or recent spinal surgery or injection
• Diabetes, long term steroid use, a weakened immune system or other conditions that make infections more likely
• Injection drug use
• Unexplained weight loss or unusual tiredness
• New numbness, pins and needles or weakness in your arms or legs

When to call 911 or go to the emergency department

Call 911 if you have back or neck pain with new weakness in your legs or arms, trouble walking, loss of bladder or bowel control, or if you feel very unwell, confused or faint.

Go to the emergency department today if you have back or neck pain together with a fever or chills, especially if you've recently had an infection, surgery or a spinal procedure, or you have diabetes or a weakened immune system.

See your family doctor within a day or two if your back pain is constant, worsening and keeping you up at night, even without a fever, and you have any of the risk factors above. Doctors will usually check blood tests for inflammation, may take blood cultures, and order an MRI if infection is suspected. If it is an infection, treatment is usually a long course of antibiotics (often around 6 weeks), and sometimes surgery.

Why your physiotherapist asks about this

At Vaughan Physiotherapy Clinic, every back and neck assessment includes questions that have nothing to do with muscles: Have you been sick recently? Any fevers, night sweats or weight loss? Any recent surgery, injections or hospital stays? Do you have diabetes or take medicines that affect your immune system?

We also look at how your pain behaves. Mechanical back pain usually changes with movement and position. Pain that stays the same no matter what you do, or keeps getting worse at night, doesn't fit that pattern. We'll also check your temperature and nerve function if something seems off.

If things don't add up, we stop treatment and refer. That could mean sending you to the emergency department the same day, or contacting your family doctor to arrange blood work and imaging. We'd always rather send you for a check and be wrong than miss something.

What physiotherapy can and can't do

Physiotherapy cannot treat a spinal infection. Hands on treatment, exercise or other therapies are not a substitute for medical care, and we won't treat your back while an infection is suspected. Questions about antibiotics or other medicines belong with your doctor or pharmacist.

Once the infection is treated and your medical team says it's safe, physio can help you get moving again: rebuilding strength, walking tolerance and confidence, and adjusting your program around any surgery or ongoing medical care.

Key takeaways

• Back pain with fever, chills or feeling unwell needs a medical check, not just rest.
• Fever is missing in about half of spinal infections, so constant, worsening or night pain with risk factors also matters.
• Recent infections, spinal procedures, diabetes, steroids and injection drug use raise the risk.
• New weakness, trouble walking or bladder or bowel changes means call 911.
• Your physio screens for these signs and will refer you to medical care.

Related reading: You may also find our guides to chronic low back pain and 5 things you need to know about back pain helpful.

The good news is that most back pain is not serious and responds well to the right plan. Learn more about everyday back pain on our mechanical low back pain page, or talk to our team if you're not sure what's going on.

Call: 905-669-1221

Visit: 398 Steeles Ave W #201, Thornhill, ON

Book online: vaughanphysiotherapy.com

Sources

Finucane, L. M., Downie, A., Mercer, C., Greenhalgh, S. M., Boissonnault, W. G., Pool-Goudzwaard, A. L., Beneciuk, J. M., Leech, R. L., & Selfe, J. (2020). International framework for red flags for potential serious spinal pathologies. Journal of Orthopaedic & Sports Physical Therapy, 50(7), 350-372. https://doi.org/10.2519/jospt.2020.9971

Berbari, E. F., Kanj, S. S., Kowalski, T. J., Darouiche, R. O., Widmer, A. F., Schmitt, S. K., Hendershot, E. F., Holtom, P. D., Huddleston, P. M., Petermann, G. W., & Osmon, D. R. (2015). Executive summary: 2015 Infectious Diseases Society of America (IDSA) clinical practice guidelines for the diagnosis and treatment of native vertebral osteomyelitis in adults. Clinical Infectious Diseases, 61(6), 859-863. https://doi.org/10.1093/cid/civ633

Durant, E. J., Copos, S., Folck, B. F., Anderson, M., Ghiya, M. S., Hofmann, E. R., Vuong, P., Shan, J., & Kene, M. (2025). Diagnostic delays are common, and classic presentations are rare in spinal epidural abscess. Western Journal of Emergency Medicine, 26(3). https://doi.org/10.5811/westjem.24985

This article is for general information and isn't medical advice. If you have any of the warning signs above, call 911 or contact your doctor right away.