Unraveling the Mystery of Low Back Pain: Common Differential Diagnoses in Modern Medical Practice

Low back pain is one of the most common complaints in primary care, with millions of patients worldwide. While musculoskeletal causes are most commonly associated with LBP, the condition may be caused by a variety of underlying conditions. Therefore, an accurate diagnosis is crucial for appropriate management. It is the role of the family physician to distinguish between benign mechanical pain and more serious pathologies, ensuring appropriate and timely treatment.

Understanding the Causes of Low Back Pain

Low back pain can be broadly divided into three categories of mechanical, neuropathic, and systemic causes. A comprehensive history, physical examination, and imaging or laboratory tests when required help distinguish among these conditions.

Common Differential Diagnoses

1. Mechanical (Musculoskeletal) Causes – The Most Frequent Culprits

Mechanical LBP accounts for the majority of cases and is often related to strain, poor posture, or degenerative changes.

• Lumbar Strain or Sprain – Acute pain due to overuse, heavy lifting, or sudden movement.

• Herniated Disc – Radicular pain ("sciatica") resulting from nerve compression, often worsened by bending or sitting.

• Facet Joint Syndrome – Localized pain exacerbated by spinal extension or twisting.

• Spondylosis & Degenerative Disc Disease – Age-related wear and tear leading to chronic stiffness and discomfort.

2. Neuropathic Causes – Nerve Involvement and Radiculopathy

When back pain is accompanied by neurological symptoms like numbness, tingling, or weakness, a nerve-related cause should be considered.

• Lumbar Spinal Stenosis – Narrowing of the spinal canal, leading to pain, numbness, and difficulty walking, especially in older adults.

• Sciatica (Radiculopathy) – Compression of the sciatic nerve, typically due to a herniated disc or spinal stenosis.

• Cauda Equina Syndrome (Emergency!) – Severe nerve compression causing bowel/bladder dysfunction and leg weakness, requiring immediate intervention.

3. Systemic & Non-Spinal Causes – The Red Flags

While less common, some cases of LBP may indicate serious underlying pathology.

• Infections (Osteomyelitis, Discitis, Epidural Abscess) – Consider in patients with fever, recent infections, or immunosuppression.

• Malignancies (Metastatic Cancer, Multiple Myeloma) – Persistent pain at rest or night, unexplained weight loss, and history of cancer raise suspicion.

• Inflammatory Conditions (Ankylosing Spondylitis, Rheumatoid Arthritis) – Chronic stiffness, pain improving with activity, and elevated inflammatory markers.

• Referred Pain (Abdominal Aortic Aneurysm, Pancreatitis, Kidney Stones) – Visceral conditions can mimic spinal pain, requiring careful assessment.

The Role of Family Physicians in Diagnosis and Management

Family physicians are at the forefront of managing LBP, ensuring a structured approach to diagnosis and treatment.

• Thorough Patient History & Examination – Identifying red flags and differentiating benign from serious causes.

• Judicious Use of Imaging – MRI or CT scans are warranted only when red flag symptoms are present or conservative management fails.

• Multimodal Treatment Strategies – Combining physical therapy, lifestyle modifications, pharmacologic treatment, and referral when necessary.

Conclusion

Low back pain is such an intricate, and multifactorial condition which always requires appropriate differential diagnosis in ascertaining the cause of it. From being able to pick the crucial differential diagnoses family doctors can assure giving the patients their proper diagnoses; appropriate plans to treat; referrals at appropriate time. Proper and broad spectrums for their causes improve results and the quality of the care given.