acute low back pain

Last edited 12/2020 and last reviewed 06/2022

Lower back pain is pain which occurs between the bottom of the rib cage and the buttock creases with or without pain in the upper legs (1).

Back pain is the largest single cause of lost working hours amongst both manual and sedentary workers; in the former, such as miners, dockers and nurses, it is an important cause of disability.

Although most people get back pain, and although there are a large number of possible causes, a precise diagnosis is made in only a few cases.

The recommended approach includes:

  • take a good history and examine the patient well
  • avoid over-investigation
  • remember the rare, but deadly, causes of pain such as aortic aneurysm or myelomatosis

Lower back pain can be divided according to its duration:

  • acute (<6 weeks)
  • sub-acute (6 weeks-12 weeks)
  • chronic (>12 weeks) (1)
Such a rigid categorization might not be useful in practice since symptoms in patients may wax and wane (1).

In acute low back pain patients can be counselled that (3):

  • prognosis for relief of pain and returning to normal activities is favourable - most patients who are initially off work, return to work within 1 month
  • most of the patients who do not return to work within 1 month will return to work within 6 months
  • however note that residual symptoms and recurrences are common

See "back pain red flags" below for more information regarding possible conditions that require immediate specialist review.