From the Guidelines
Low back pain can be caused by various medical conditions, including herniated or bulging discs, degenerative disc disease, spinal stenosis, osteoarthritis, spondylolisthesis, muscle or ligament strains, osteoporosis-related fractures, fibromyalgia, and inflammatory conditions like ankylosing spondylitis, as well as kidney stones, infections, and tumors. The most recent and highest quality study, published in 2021 in the Journal of the American College of Radiology 1, emphasizes the importance of a focused history and physical examination to classify patients into broad categories, such as nonspecific low back pain, back pain potentially associated with radiculopathy or spinal stenosis, and back pain potentially associated with another specific spinal cause.
Common Causes of Low Back Pain
- Herniated or bulging discs, where the soft cushioning between vertebrae protrudes and may press on nerves, causing pain that can radiate down the legs (sciatica)
- Degenerative disc disease, which occurs when spinal discs naturally wear down with age, reducing their shock-absorbing capacity
- Spinal stenosis, involving narrowing of the spinal canal, compressing nerves and causing pain, especially when standing or walking
- Osteoarthritis, affecting the facet joints of the spine, leading to inflammation and pain
- Spondylolisthesis, occurring when one vertebra slips forward over another, causing instability and pain
- Muscle or ligament strains from improper lifting or sudden movements
- Osteoporosis-related fractures
- Fibromyalgia
- Inflammatory conditions like ankylosing spondylitis
- Kidney stones, infections, and tumors, which can also refer pain to the lower back
Importance of Accurate Diagnosis
Accurate diagnosis is crucial to determine the underlying cause of low back pain and to guide treatment decisions. The American College of Physicians and the American Pain Society recommend a focused history and physical examination, reassurance, initial pain management medications if necessary, and consideration of physical therapies without routine imaging in patients with nonspecific low back pain 1.
Treatment Options
Treatment depends on the specific cause and may include:
- Physical therapy
- Medication for pain and inflammation
- Surgical intervention for structural problems that don't respond to conservative measures It is essential to note that imaging studies are not necessary for uncomplicated acute low back pain and/or radiculopathy, but may be considered for patients who have had up to 6 weeks of medical management and physical therapy with little or no improvement, or for those presenting with red flags, raising suspicion for a serious underlying condition, such as cauda equina syndrome, malignancy, fracture, or infection 1.
From the Research
Medical Causes of Lumbar (Lower Back) Pain
The medical causes of lumbar (lower back) pain can be categorized into several distinct sources, including:
- Axial lumbosacral pain
- Radicular pain
- Referred pain 2 Some of the specific etiologies of low back pain include:
- Myofascial pain
- Facet joint pain
- Sacroiliac joint pain
- Discogenic pain
- Spinal stenosis
- Failed back surgery 2
Mechanical and Nonmechanical Disorders
Low back pain can also be caused by mechanical and nonmechanical disorders, including:
- Osteoarthritis
- Lumbar spinal stenosis (mechanical)
- Infectious, neoplastic, rheumatologic, endocrinologic, vascular, and gynecologic disorders (nonmechanical) 3 Mechanical low back pain arises intrinsically from the spine, intervertebral disks, or surrounding soft tissues 4
Musculoskeletal Causes
The vast majority of patients with low back pain have a musculoskeletal cause, with 90% of patients recovering within a month with conservative treatment 5 Ninety percent of patients with acute low back problems recover within a month with very conservative treatment, but recurrent attacks of pain are common, and approximately 10% of patients develop chronic low back pain 5
Other Causes
Low back pain can also be caused by other factors, including:
- Nociceptive, neuropathic, and nociplastic pain
- Soft tissue, vertebrae, zygapophyseal and sacroiliac joints, intervertebral discs, and neurovascular structures 6 The biopsychosocial model posits low back pain to be a dynamic interaction between social, psychological, and biological factors that can both predispose to and result from injury 6