Left back pain is most commonly caused by muscle strain, sprain, or injury in otherwise healthy adults. Other common causes of left back pain include spinal deformities, a herniated disk, or osteoarthritis in the hips, legs or back. Certain ailments or conditions, like pregnancy or obesity, can aggravate existing back issues, causing pain. Less common causes of left back pain can include illness or infection.
Muscle strain is the most common cause of left back pain. This can occur any time the muscles of the back or hip are overworked or are stretched in a sudden and jarring manner. In the hip area, muscle strains can lead to pain in the lower back as well. The effects of limping or favoring the injured area may cause pain in otherwise unaffected parts of the back.
Spinal issues like stenosis, or narrowing of the spinal canal, can occur with age and are a common cause of lower left back pain in senior citizens. Vertebra problems like spondylolysis or spondylolisthesis may become painful when aggravated by an injury or muscle strain to the left back or hip. An injury may cause a vertebra to slip slightly out of position, triggering back pain in the left or right side.
Osteoarthritis, joint pain that occurs with age, is another common cause of left back pain. Arthritis may cause pain in the back upon rising in the morning or when changing position after being seated for a long time. Some people with arthritis feel it is more painful in cold or rainy weather. Left back pain caused by arthritis may originate in the hip or leg region as well.
Conditions like pregnancy may cause back pain in one or both sides as the weight of the baby increases and more pressure is put on the muscles of the torso and back. Back pain caused by pregnancy will generally resolve itself after delivery. Obesity or sudden weight gain can also impact the large muscles at either side of the back, causing pain. Losing weight will often help reduce or eliminate back and joint pain.
There are different ways of treating left back pain, including pain medication, hot or cold compresses, braces, and surgery. The most common left back ailments, like muscle strain, can be treated at home or with a simple visit to the doctor's office. More severe issues may require more extensive treatment, and persistent back pain of unknown origin should be investigated by a physician.