Low back pain usually involves spasm of the large, supportive muscles alongside the spine. Any injury to the back may produce muscle spasms and stiffness.
Pain caused by muscular strain is usually confined to the back. Occasionally, it may radiate into the buttocks or upper leg(s).
The onset of pain may be immediate or may occur a few hours after the exertion or injury. Often the cause is not obvious.
muscle strain, pulled muscle in the back, or similar injury (the most common cause)
muscle aches related to a viral infection
menstruation or premenstrual syndrome (PMS)
prolonged sitting in a person who is susceptible to back problems
in children: scoliosis, Scheuermann's kyphosis, or spondylolysis
nonspecific back pain
Less common, but serious causes:
pressure on a nerve root (for example, spinal stenosis or herniated nucleus pulposus)
ruptured vertebral disk
Note: There may be other causes of low back pain. This list is not all-inclusive, and the causes are not presented in order of likelihood. The causes of this symptom can include unlikely diseases and medications. Furthermore, the causes may vary based on age and gender of the affected person, as well as on the specific characteristics of the symptom such as location, quality, time course, aggravating factors, relieving factors, and associated complaints.
Call your healthcare provider right away if:
there is significant pain
there is an associated, unexplained fever.
there is redness or swelling on the back or spine.
the pain travels down the legs below the knee (which suggests pressure on the nerves as they leave the spinal cord).
there is weakness or numbness in a leg.
Physical examination will focus on the back, the abdomen, and the extremities, with special attention to testing the nerve function of the legs.
If the physical examination indicate damage to the nerves leaving the spinal cord, a myelogram (X-ray or CT of the spine after dye has be injected into the spinal column) may be necessary. Alternatives include a CT of lumbosacral spine or MRI of lumbosacral spine.
Hospitalization, traction, or surgery should only be considered if nerve damage is present or the condition fails to heal for a prolonged period.