Low back pain can range in intensity from a dull, constant ache to a sudden, sharp sensation that leaves the person incapacitated. Pain can begin abruptly as a result of lifting something heavy or by trauma from an accident; or it can develop over time due to age-related changes of the spine. Sedentary lifestyles also can contribute to low back pain, especially when a weekday routine of getting too little exercise is punctuated by strenuous weekend workout.
Most low back pain is acute, or short term, and lasts a few days to a few weeks. It tends to resolve on its own with self-care and there is no residual loss of function. The majority of acute low back pain is mechanical in nature, meaning that there is a disruption in the way the components of the back (the spine, muscle, intervertebral discs, and nerves) fit together and move.
Subacute Low Back Pain is defined as pain that lasts between 4 and 12 weeks. Chronic Low Back Pain is defined as pain that persists for 12 weeks or longer, even after an initial injury or underlying cause of acute low back pain has been treated.