Low back pain is one of the most frequent medical complaints reported to doctors each year. Yet getting an accurate diagnosis of the source of persistent backpain can be a difficult and trying experience for patient and doctor alike.

Successful treatment of chronic lower back pain requires an understanding of the cause. The root cause will usually fall in one of these categories: muscle strain, pinched nerve, bone fractures, arthritis, infection, or disease.

Pulled muscle

Muscle strains, or “pulled muscles” in the lower back are the most frequent cause of lower back pain. They are also the most easily prevented.

A muscle strain occurs when the muscle is overstretched or torn. Overloading back muscles by improperly lifting heavy objects, falling down, or unexpectedly twisting the back can pull back muscles.

Muscle strains also result from repetitive movements or maintaining a position too long without moving. Muscles become fatigued and more prone to injury when the same muscle repeatedly takes the brunt of an activity.

Poor posture, standing for long periods, or sitting without proper care for ergonomic positioning can also lead to back muscle strains.

Once strained, inflammation from the healing process causes pain and may trigger painful muscle spasms. Fortunately most cases of lower back pain caused by mild to moderate back muscle strains heal on their own in a matter of weeks.

Pinched nerve

Pinched nerves in the lumbar area of the spine cause most cases of non-muscle strain related low back pain. Of these, herniated discs are the most frequent source of complaint.

Composed of a soft jelly-like interior ringed by a tougher fibrous outer casing, spinal discs act as shock absorbers between the vertebrae. Excess pressure or movements such as improper lifting may cause the interior to bulge or rupture completely through the exterior wall (disc herniation). When this occurs the inner core may press against and irritate spinal nerves causing pain in the lower back and even down the legs (sciatica).

A narrowing of the spinal canal which pressures the spinal cord or nerve roots can also cause lower back pain. Known as spinal stenosis, this condition is caused by normal tissue degeneration during the age process, typically affecting individuals over 50 years old. Excessive bone growth or herniated discs can also lead to spinal stenosis.

Arthritis

The leading cause of disability in people over 55 years old, arthritis damages the joints in the body. Arthritis results from joint trauma, infection, inflammation or aging. The degenerative joint disease osteoarthritis  is the most common form.

Back pain can result directly from osteoarthritis when it impacts the facet joints along the spine. Back pain can also be caused indirectly by osteoarthritis when it affects other joints such as the hips. When your body overcompensates to avoid pain in the affected joints, muscle imbalances can form leading to lower back pain.

Ankylosing spondylitis, or spondyloarthritis , is a form of inflammatory arthritis which attacks spine and sacroiliac joints in the lower back. Typically affecting people in their late teens to early 30s, ankylosing spondylitis causes chronic lower back pain and often causes fusion of the spine.

Bone fractures

Lower back pain from compression fractures are more commonly found in older individuals suffering from osteoporosis, a disease that causes bones to become thin and brittle. Even a strong sneeze can cause a compression fracture in some cases.

A condition known as spondylolysis , caused by developmental defects in the vertebrae, can lead to spondylolisthesis , a condition where one vertebra slides across another during certain activities instead of maintaining its proper position. Spondylolisthesis can irritate or place painful pressure on nerve roots.

Blunt force trauma, such as from an auto accident, or compression of the spine caused by falling on the buttocks or head can also cause fractures of the vertabrae.

Infection, disease, and other causes of low back pain

Bacterial infections carried to the spine from elsewhere in the body, or directly introduced during surgery, spinal injections or through injury can cause lower back pain. The infection may lodge in a bone (osteomyelitis), spinal disc, or the spinal cord itself.

Spinal deformities such as scoliosis  and kyphosis can cause lower back pain in adults, especially if the condition is left untreated.

Paget’s disease, which causes abnormal bone growth, and spinal tumors can also cause lower back pain by pressuring the spinal cord or nerve roots.

Lower back pain can mean double trouble

When lower back pain persists over time, muscle strains either from the cause of pain or how muscles are used to avoid pain can lead to muscle imbalances and even permanent changes in the spinal structure if left unchecked.

Fortunately most cases of lower back pain are easily treatable without surgery when properly diagnosed at an early stage. Here are some of the most common low back pain treatments