Back pain is a common reason for patients to present to their primary care provider or an emergency department. Accurately diagnosing and treating back pain can be challenging due to the complex anatomy of the spine, the variety of pain generators, and the numerous conditions that can affect the spine. This article will provide the basics of spinal anatomy and will review common pain triggers to be aware of.
Spinal Anatomy
The spine consists of 33 vertebrae — 7 cervical (neck), 12 thoracic (mid back), 5 lumbar (low back), 5 sacral (pelvis) and 4 coccygeal (tailbone). The vertebrae are strong bony structures connected by a complex of soft tissue structures, including intervertebral discs, facet joints, joint capsules, ligaments and paraspinal muscles. These supporting structures play an important role in facilitating and controlling movements of the spine, such as flexion (forward bending), extension (backwards bending), lateral bending (sideways bending), and rotation (twisting). The spine is designed to maintain upright posture and support weight along its entire length. Therefore, these structures are constantly under stress as they support normal spine function.
The vertebrae also serve to protect the spinal cord and its branching nerve roots. Each vertebra, from the cervical spine to sacral spine, has corresponding nerve roots that function to provide limb movement, bodily sensation, and normal organ function, including bowel and bladder control.
When the spine and its associated structures are damaged, a person may experience neck, back, arm, and leg pain. In severe cases, this can lead to weakness or bowel and bladder dysfunction.
Painful Spinal Conditions
The majority of back pain is not serious or life-threatening. Certain red flag features of back pain may point to more serious underlying causes and warrant medical evaluation. These include but are not limited to fever, night sweats, unintentional weight loss, arm or leg weakness, and bowel or bladder dysfunction.
A number of conditions can affect the spine and its surrounding structures to cause pain. These conditions include:
Degenerative: As a person ages, the spine can slowly wear out and result in painful arthritis between the vertebrae. Degenerative disc disease, cervical and lumbar stenosis (spinal canal narrowing) and disc herniations fall into this category.
Trauma: Injury to the spine can result in a variety of painful conditions, including muscle strain, ligament sprain, disc herniation or vertebral fractures. Certain injuries may lead to back pain or nerve damage, which may result in weakness, numbness, or paralysis in either the arms or legs depending on the location of injury. Some injuries may be severe enough to require surgery.
Metabolic: Abnormal bone metabolism or mineral deficiencies, such as calcium, may result in poor bone quality. Osteoporosis is an example. Patients with osteoporosis are at greater risk of sustaining nontraumatic compression fractures of the spine.
Infection: Infections from other areas of the body may spread to structures in the spine. Infections can break down the spine’s stabilizing structures and result in pain and possibly neurologic injury. Infections may also occur after surgery. Patients with a compromised immune system, diabetes or a history of intravenous substance use are at an increased risk of spine infections. Antibiotics, and possibly surgery, are necessary treat a spine infection.
Tumors: Both benign and malignant tumors may originate in the spine. Additionally, malignant tumors from other areas of the body may metastasize (spread) to the spine. Tumors near the spine may cause pain, fracture or neurologic injury. Tumors may require chemotherapy, radiation therapy, or surgery for treatment.
Inflammatory: Conditions other than infection or malignancies that cause inflammation, such as ankylosis spondylitis and rheumatoid arthritis, may result in back pain.
Congenital: Some individuals may be born with conditions that predispose to back pain. Conditions include scoliosis (abnormal spine curvature) and tethered spinal cord (spinal cord gets stuck to adjacent protective structures).
Postural: Standing for long periods of time can result in back pain. This is most often due to muscle fatigue or strain. Maintaining a healthy weight and routine core and back strengthening exercises can be helpful in preventing and treating postural back pain.
Referred pain: Pain from other organs may radiate to the back. Examples include pain that originates from conditions involving the aortic artery, lungs or abdominal organs.
Ultimately, it is important to understand the quality, duration and severity of symptoms when considering the underlying cause of back pain. A careful evaluation by a medical professional is recommended to identify causes of back pain. Diagnostic imaging is often required to assist with the diagnosis. If specific spine treatments are needed, precise management from a spine specialist can target the pain generators to get you back to your life.
