Low back pain is a common problem affecting most adults at some point during their lifetime. At any one time, around 1 in 5 adults will report symptoms of low back pain, rising to 40% when asked if they have experienced symptoms during the previous month. The majority of people who experience an episode of low back pain will improve over time. However a sizeable proportion experience repeated episodes or recurrences, and some report continuous symptoms for many years. A wide range of factors are linked to both the onset and persistence of low back pain. Some studies have related age and gender to low back pain, but the link overall is equivocal. Work-related factors such as heavy lifting, and socio-demographic factors such as smoking and obesity have been linked with the onset of low back pain. High levels of functional impairment and the presence of pain radiating to the leg have been cited as factors associated with a poor prognosis among primary care consulters with low back pain. Other characteristics associated with both the development and the persistence of low back pain include psychological factors such as depression and anxiety and workplace factors such as job satisfaction. Low back pain places large demands on health, social and welfare systems. Further research is needed to identify practical interventions to reduce this burden from low back pain.