Low Back Pain: Common Causes in Plain English

By the Kessler Spine & Rehab Clinical Team

Educational, not medical advice. Only a provider who has examined you can say what your symptoms or reports mean for you.

Low back pain is one of the most common health problems adults deal with.¹ It can show up after lifting, after a long day on your feet, after a fall or a crash, or for no reason you can point to. This guide explains the most common sources of low back pain in everyday language, what a careful exam looks for, and which symptoms mean you should get emergency care instead of waiting.

Acute vs. Chronic Back Pain

Health organizations usually sort back pain by how long it has lasted:

• Acute back pain is recent, lasting days to a few weeks.²
• Chronic back pain has lasted longer than about 12 weeks (roughly three months).¹

The label describes time, not severity. Short-term pain can be intense, and long-term pain can be mild. The label also doesn't tell you the cause.

Common Sources of Low Back Pain

The low back is a stack of five vertebrae with discs between them, small joints in the back called facet joints, and many muscles, tendons, and ligaments. Nerve roots leave the spine on each side. Pain can come from any of these, and more than one can be involved at the same time.

Muscle strain and ligament sprain. A strain involves a muscle or tendon; a sprain involves a ligament. Both can follow lifting, twisting, a sudden movement, or an impact.³ We explain the difference in Strain vs. Sprain.

Disc changes. Discs can bulge or herniate. If disc material irritates a nearby nerve root, pain or tingling may travel into the buttock or leg.⁴ Our guide to disc bulge vs. herniation explains the report terms.

Arthritis and facet joint changes. Wear-related changes in the small joints and discs become more common with age. They often appear on imaging in people who have no pain at all, so they are considered together with the exam.⁵

Spinal stenosis. Narrowing of the spinal canal or the openings where nerves exit can cause leg pain, heaviness, or tingling with standing or walking. See Spinal Stenosis in Plain English.

Spondylolisthesis. This means one vertebra sits forward or backward on the one below it. It may or may not be related to symptoms. See Spondylolisthesis.

Nerve root irritation (sciatica). Pain that travels down the leg, sometimes with numbness or weakness, is often called sciatica. See Sciatica: Pain That Travels Down a Leg.

Pain from outside the spine. Some back pain comes from other organs or medical conditions, such as kidney stones or infections. That's one reason a full history matters.¹

For many people, no single structure can be identified as the source. Guidelines often call this nonspecific low back pain. It's a common and real category, not a sign that the pain is imagined.⁶

Everyday Factors That Can Play a Role

Factors linked with back pain include a low activity or fitness level, extra body weight, jobs that involve heavy lifting or twisting, smoking, and stress, anxiety, or depression.¹ These are general associations. They don't explain any one person's pain on their own.

Do I Need an X-Ray or MRI?

Not automatically. A review of randomized trials found that routine, immediate imaging for low back pain without warning signs didn't improve pain or function compared with usual care.⁷ Imaging becomes more useful when there are red flags, significant nerve findings, or symptoms that aren't following the expected course. A provider who has examined you decides whether any test is appropriate. Our guide X-Ray vs. MRI vs. CT explains what each test shows.

What a Careful Exam Looks For

A back exam usually includes:

• History: how and when the pain started, what makes it better or worse, earlier back problems, prior records or imaging, and your general health
• Movement: how your low back and hips move, and which motions reproduce your symptoms
• Neurological screening: strength, reflexes, and sensation in the legs, which can point to whether a nerve root may be involved
• Orthopedic tests: specific positions and movements that help narrow down possible sources
• Red-flag screening: questions about fever, weight loss, cancer history, bladder or bowel changes, and recent trauma

The exam describes what is found. It doesn't, by itself, settle every question about cause, and findings are documented objectively.

Care Options People Often Discuss

A 2017 American College of Physicians guideline lists non-drug options, such as superficial heat, massage, acupuncture, and spinal manipulation, as first choices for many adults with recent low back pain, and exercise-based approaches for longer-lasting pain.⁶ Not every option fits every person.

At our office, when care is appropriate it may include hands-on care, rehab exercises, and, when your doctor determines it is appropriate, Hill flexion-distraction. Every plan is individual, and we don't promise a specific result or timeline. Learn more on our back pain care page.

⚠️ Call 911 or go to the ER if back pain comes with numbness in the groin or inner thighs, new loss of bladder or bowel control, rapidly worsening weakness in a leg, or fever and feeling very ill. Get emergency care for severe back pain after a serious fall or crash.

If Your Back Pain Started After a Car Crash

Back pain after a collision deserves an evaluation, even when it seems mild at first. Our Bradenton car accident page explains what a first visit looks like.

Frequently Asked Questions

What is the most common cause of low back pain?
Muscle and ligament strains and sprains are among the most common causes. For many people, no single structure can be identified, which guidelines call nonspecific low back pain.

When is low back pain considered chronic?
Back pain is generally called chronic when it has lasted longer than about 12 weeks. The label describes how long pain has lasted, not how severe it is or what is causing it.

Do I need an MRI for low back pain?
Not automatically. Research shows routine, immediate imaging without warning signs doesn't improve outcomes for most people. A provider who has examined you decides whether any imaging is appropriate.

When is back pain an emergency?
Call 911 or go to the ER for numbness in the groin or inner thighs, new loss of bladder or bowel control, rapidly worsening leg weakness, fever with back pain, or severe pain after a serious fall or crash.

Have Questions?

Our Bradenton team is happy to talk through your questions in plain language. An exam looks at your history, your symptoms, and how you move. It is not a promise of any particular finding, test, or result.

📞 941-877-0317
Bradenton: 3633 Cortez Rd W, Ste A9, Bradenton, FL 34210
Bradenton hours: Monday–Thursday 9:00 AM–12:00 PM and 1:30 PM–6:00 PM; Friday 9:00 AM–12:00 PM

Auto accident patients: walk-ins and same-day evaluations are welcome during office hours at our Bradenton office. For other care, please call 941-877-0317 to schedule.

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⚠️ If you think you have a medical emergency, call 911 or go to the nearest emergency room.

Related reading: Back Pain Care · Sciatica · Disc Bulge vs. Herniation · FAQ · Patient Education

Sources

1. National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS). Back Pain. https://www.niams.nih.gov/health-topics/back-pain
2. MedlinePlus Medical Encyclopedia. Low back pain – acute. https://medlineplus.gov/ency/article/007425.htm
3. American Academy of Orthopaedic Surgeons (AAOS) OrthoInfo. Low Back Pain. https://orthoinfo.aaos.org/en/diseases--conditions/low-back-pain/
4. AAOS OrthoInfo. Herniated Disk in the Lower Back. https://orthoinfo.aaos.org/en/diseases--conditions/herniated-disk-in-the-lower-back/
5. Brinjikji W, et al. Systematic literature review of imaging features of spinal degeneration in asymptomatic populations. AJNR Am J Neuroradiol. 2015;36(4):811–816. https://pubmed.ncbi.nlm.nih.gov/25430861/
6. Qaseem A, et al. Noninvasive treatments for acute, subacute, and chronic low back pain: a clinical practice guideline from the American College of Physicians. Ann Intern Med. 2017;166(7):514–530. https://pubmed.ncbi.nlm.nih.gov/28192789/
7. Chou R, et al. Imaging strategies for low-back pain: systematic review and meta-analysis. Lancet. 2009;373(9662):463–472. https://pubmed.ncbi.nlm.nih.gov/19200918/

This article is for general educational purposes only and isn't medical or legal advice. It doesn't describe any particular patient or case, and it isn't an opinion about any individual. Reading it doesn't create a doctor–patient relationship. If you think you have a medical emergency, call 911 or go to the nearest emergency room.