What causes lower back pain?

When does lower back pain need urgent medical care?

Lower back pain needs urgent assessment when it comes with new bladder or bowel problems, numbness around the groin, significant weakness, serious injury or signs of severe illness. These symptoms can indicate conditions that need prompt treatment, including compression of the nerves that control bladder and bowel function. VA/DoD clinical guideline

Get emergency care now for:

• New inability to urinate, loss of bladder or bowel control, or numbness around the groin and inner thighs.
• Severe or rapidly worsening weakness in one or both legs.
• Major trauma followed by severe back pain, particularly if you cannot stand or walk safely.

These are warning signs for serious neurological injury or fracture. Don’t wait for an exercise program or a routine appointment to address them. VA/DoD clinical guideline

Seek urgent medical assessment for back pain with fever or feeling seriously unwell, especially if you have a weakened immune system or a recent serious infection. A history of cancer with new or unusual back pain also needs prompt assessment, particularly with unexplained weight loss. These features do not establish a diagnosis, but they change what a clinician needs to investigate. VA/DoD clinical guideline

A checklist cannot rule out every serious condition. If symptoms are rapidly changing or you feel acutely ill, seek medical care even if your experience doesn’t match these examples exactly.

What are the most common lower back pain causes?

The most common category is nonspecific lower back pain, where an assessment does not identify a single disease or damaged structure that adequately explains the symptoms. That is the category the WHO estimates accounts for about 90% of cases.

“Nonspecific” describes the limits of identifying the cause. Your pain is still real.

Several factors can matter at once, including physical demands, activity levels and psychological or social stress. The evidence does not support confidently assigning every episode to one lifting technique, one posture or one weak muscle. The physical therapy clinical practice guideline by Delitto and colleagues describes these factors as multifactorial and notes that individual risk factors generally have weak relationships with the development of back pain.

Imagine your back starts hurting after moving furniture. The lifting gives you useful information about when the pain began. It does not tell you, by itself, whether a particular muscle, ligament, joint or disc is responsible. Those structures can all be involved in back pain, and symptoms alone may not distinguish them. National Institute of Arthritis and Musculoskeletal and Skin Diseases

This is why a useful assessment asks what happened, what you can do now, and whether there are nerve symptoms or signs of another condition. The job is to make a sound care decision with the information available. VA/DoD clinical guideline

Can a muscle strain or ligament sprain cause lower back pain?

A muscle strain or ligament sprain can cause lower back pain, including after lifting, twisting or an injury. A strain affects a muscle or tendon; a sprain affects a ligament, which connects bones. NIAMS’s back pain overview

The difficult part is confirming that this is what happened. Pain that begins during an activity can suggest a musculoskeletal problem, but it does not reliably identify the exact tissue involved. Muscles, ligaments, joints and discs can produce overlapping symptoms. NIAMS

You don’t need to turn that uncertainty into a theory about having lifted “wrong.” Tell a clinician what you were doing, when the pain started and how your movement has changed. Those observations are more useful than arriving certain that you have torn a muscle.

Can a disc problem cause lower back pain or sciatica?

A disc problem can cause lower back pain, and a herniated disc can irritate or compress a nearby nerve, producing symptoms into the leg. Discs sit between the bones of the spine; a herniation occurs when inner disc material pushes outward. NIAMS

Pain that travels from the back or buttock into the leg, particularly with tingling, numbness or weakness, raises the possibility of nerve involvement. This pattern is often called sciatica. An assessment is needed to understand the source and check neurological function. WHO

Leg pain does not automatically mean you need surgery. NICE recommends considering spinal decompression for sciatica when nonsurgical treatment has not improved pain or function and imaging findings fit the person’s symptoms. That is a specific decision based on several pieces of evidence. NICE

Arrange an assessment if pain travels down your leg with numbness, tingling or weakness. Rapidly worsening weakness, new bladder or bowel dysfunction, or numbness around the groin needs emergency care. VA/DoD clinical guideline

What other conditions can cause pain in the lower back?

Other causes of lower back pain include spinal stenosis, inflammatory arthritis, fractures, infection and cancer; sometimes pain comes from a problem outside the spine. These conditions need different evaluation and care, which is why a history and examination matter. NIAMS, NICE

Spinal stenosis is narrowing around the spinal cord or nerves. It can produce back or leg symptoms. Inflammatory conditions such as axial spondyloarthritis can also affect the spine. Neither diagnosis can be made from the words “lower back pain” alone. NIAMS

Fracture risk deserves particular attention after an injury and in people with osteoporosis or prolonged corticosteroid use. Infection risk changes with factors such as immune suppression or a recent infection. A clinician uses those details alongside the symptoms and examination to decide whether testing is needed. VA/DoD clinical guideline

Pain felt in the back can also come from conditions such as kidney stones. The location of pain is one clue, not a diagnosis. Tell your clinician about symptoms outside your back as well. NIAMS

Is poor posture or a weak core the cause of lower back pain?

Poor posture or a weak core cannot be assumed to be the cause of lower back pain from symptoms alone. Research describes back pain risk as multifactorial, and most uncomplicated episodes do not have one confidently identifiable cause. Delitto and colleagues

If sitting at your desk hurts, that observation matters. It can help you identify an activity you need to modify and something to discuss during an assessment. It does not prove that your sitting position damaged your spine.

The same distinction applies to exercise. A strengthening program may help without establishing that weakness caused the problem. A 2023 systematic review prepared for the WHO guideline found that structured exercise probably produces modest improvements in pain and function for chronic primary low back pain. Evidence for individual exercise types varied, so there is no basis for prescribing one universal “core fix” to everyone.

Can stress affect lower back pain?

Stress and other psychological or social factors can affect the experience of lower back pain and the course of recovery, alongside physical factors. Considering them is part of assessing the whole problem. Delitto and colleagues, VA/DoD clinical guideline

That does not mean a clinician should dismiss pain as stress. Back pain still needs an appropriate history and examination. But if you’re worried every movement will cause injury, avoiding activities, or struggling with demands at work, those details can change what support is useful.

NICE recommends considering combined physical and psychological care for persistent lower back pain when there are substantial obstacles to recovery, or when previous treatment has not worked. NICE

You can bring those concerns into an appointment directly: “I’m worried walking will make this worse,” or “I’m avoiding tasks because I don’t know what is safe.” That gives the clinician a concrete question to address.

Do you need an MRI to find the cause of lower back pain?

Most uncomplicated episodes of lower back pain do not need an immediate MRI, because imaging is useful when its result is likely to change care. NICE advises against routine imaging in nonspecialist settings and recommends selective imaging in specialist care. NICE

Wanting a scan makes sense. You have pain, and you want someone to look inside and explain it. But a scan has to be interpreted alongside your symptoms and examination. Finding a structural change does not, by itself, establish that it explains your pain. VA/DoD clinical guideline

“No scan today” should still come with a plan. Ask what the assessment suggests, what to do next and which changes should bring you back. New or worsening symptoms can change the need for investigation. NICE

What should you do if there are no urgent warning signs?

For many uncomplicated episodes, the starting point is advice tailored to your situation, continued normal activity as tolerated and appropriate exercise. Prolonged bed rest is generally discouraged. NICE, VA/DoD clinical guideline

“Stay active” still needs to mean something practical. Ask which activities are reasonable for you now, how to adjust a difficult task and when to seek reassessment. Advice should account for your capabilities and symptoms. NICE

For example, tell your clinician if you can walk comfortably for a few minutes but struggle to finish your commute. That gives you a specific function to work on and track. Pain intensity matters, but walking, daily activities and participation in work also help describe how you’re doing. VA/DoD clinical guideline

Arrange an assessment if pain is worsening, is not improving with self care, repeatedly returns, or substantially disrupts sleep or daily life. New leg numbness or weakness also deserves assessment. NIAMS

Can exercise help when the exact cause is unclear?

Exercise can help many people with nonspecific lower back pain even when no single tissue has been identified as the cause. For chronic primary low back pain, the WHO evidence review found modest average improvements in pain and function compared with no intervention.

Average benefit is not a promise about your outcome. The exercise studies involved selected participants, and their findings cannot establish that an exercise plan is appropriate for someone with an undiagnosed fracture, infection or progressive neurological problem. The same review reported temporary increases in pain in some exercise comparisons.

The choice of exercise should account for your needs, preferences and capabilities. You should also understand how the plan changes over time. NICE

A 2025 systematic review of exercise progression found promising results for programs with defined progression criteria, but the studies varied and long term evidence was limited. That supports being deliberate about progression. It does not establish one schedule or pain threshold that is right for everyone.

How can GoodMetal help with a lower back exercise plan?

GoodMetal can help you follow a structured exercise plan through programs built by its licensed physical therapists with 10+ years of experience each.

They designed the structure every plan follows: which exercises are included, how the weekly sessions are arranged and how the phases progress. That gives you a plan for pacing the work, moving forward and understanding when to hold back. The guided exercise video library shows you the movements, so you have more to work from than an exercise name.

GoodMetal also offers proactive plan adjustments, text access to a care team and care coordination. The practical value is having support around the plan when following it becomes difficult or your needs change.

The programs are general templates, not individualized medical care. They cannot determine what caused your pain or rule out serious disease. Symptoms that need an examination or urgent care should be assessed before you rely on an exercise program.

What should you bring to a back pain appointment?

Bring a clear account of when the pain began, how it affects your daily life and whether you have symptoms outside the back. Those details support the history and examination recommended in the VA/DoD clinical guideline.

Write down:

• When the pain started and whether there was an injury or change in activity.
• Where you feel it, including whether it travels into a leg.
• Any numbness, weakness, fever, urinary symptoms or bowel changes.
• What has become difficult, such as sleeping, walking or working.
• What you have tried and what happened afterward.
• Relevant medical history, including cancer, osteoporosis, recent infection and steroid use.

Then ask: “What do you think is causing this, what remains uncertain, and what would change the plan?”

You may leave without one exact tissue diagnosis. You should leave understanding the next step and when to come back.

This article provides general education. It cannot diagnose your symptoms or replace an examination by a qualified healthcare professional.

Sources

[1] Low back pain; [2] Low Back Pain: Clinical Practice Guidelines Linked to the International Classification of Functioning, Disability, and Health from the Orthopaedic Section of th; [3] Back Pain Symptoms, Types, & Causes | NIAMS; [4] Recommendations | Low back pain and sciatica in over 16s: assessment and management | Guidance | NICE; [5] Systematic Review to Inform a World Health Organization (WHO) Clinical Practice Guideline: Benefits and Harms of Structured Exercise Programs for Chronic Primar; [6] Therapeutic Exercise Progression in Patients with Nonspecific Low Back Pain: A Systematic Review.; [7] VA/DoD Clinical Practice Guideline: Diagnosis and Treatment of Low Back Pain - PMC; [8] Assessment and Treatment of Acute Low Back Pain (ALBP): A Systematic Review.; [9] WHO guideline for non-surgical management of chronic primary low back pain in adults in primary and community care settings.