Editing Low back pain (section)

===Classification===
There are a number of ways to classify low back pain with no consensus that any one method is best.<ref name=manusov_2012_diag/> There are three general types of low back pain by cause: mechanical back pain (including nonspecific musculoskeletal strains, [[herniated disc]]s, compressed [[nerve root]]s, [[degenerative disc disease|degenerative disc]]s or [[degenerative joint disease|joint disease]], and broken vertebra), non-mechanical back pain ([[neoplastic disease|tumors]], inflammatory conditions such as [[spondyloarthritis]], and infections), and [[referred pain]] from internal organs ([[biliary colic|gallbladder disease]], [[kidney stone]]s, [[kidney infection]]s, and [[aortic aneurysm]], among others).<ref name=manusov_2012_diag/> Mechanical or musculoskeletal problems underlie most cases (around 90% or more),<ref name=manusov_2012_diag/><ref name=cohen_2008>{{cite journal | vauthors = Cohen SP, Argoff CE, Carragee EJ | title = Management of low back pain | journal = BMJ | volume = 337 | pages = a2718 | date = December 2008 | pmid = 19103627 | doi = 10.1136/bmj.a2718 | s2cid = 78716905 }}</ref> and of those, most (around 75%) do not have a specific cause identified, but are thought to be due to muscle strain or injury to ligaments.<ref name=manusov_2012_diag/><ref name=cohen_2008/> Rarely, complaints of low back pain result from systemic or psychological problems, such as [[fibromyalgia]] and [[somatoform disorders]].<ref name=cohen_2008/>

Low back pain may be classified based on the signs and symptoms. Diffuse pain that does not change in response to particular movements, and is localized to the lower back without radiating beyond the [[buttock]]s, is classified as ''nonspecific'', the most common classification.<ref name=manusov_2012_diag/> Pain that radiates down the leg below the knee, is located on one side (in the case of disc herniation), or is on both sides (in spinal stenosis), and changes in severity in response to certain positions or maneuvers is ''radicular'', making up 7% of cases.<ref name=manusov_2012_diag/> Pain that is accompanied by red flags such as trauma, fever, a history of cancer or significant muscle weakness may indicate a more serious underlying problem and is classified as ''needing urgent or specialized attention''.<ref name=manusov_2012_diag/>

The symptoms can also be classified by duration as acute, sub-chronic (also known as sub-acute), or chronic. The specific duration required to meet each of these is not universally agreed upon, but generally pain lasting less than six weeks is classified as ''acute'', pain lasting six to twelve weeks is ''sub-chronic'', and more than twelve weeks is ''chronic''.<ref name=koes_2010/> Management and prognosis may change based on the duration of symptoms.