Prognosis

Most people with acute low back pain are back at work within a month and fully recover within a few months. According to one study, about a third of patients with uncomplicated low back pain significantly improved after a week; two thirds recovered by 7 weeks.

However, studies now suggest that up to 75% of patients suffer at least one recurrence of back pain over the course of a year. In another study, after 4 years, less than half were symptom-free. Some doctors are approaching the problem as one that is not necessarily curable and which needs a consistent on-going approach.

Specific conditions can determine the rate of improvement:

  • In the majority of patients with herniated disks, the condition improves (although the actual physical improvement may be slower than the reduction in pain). Researchers attempted to identify factors most likely to predict an elevated risk for recurrent pain and found that only depression was a significant factor in the majority of those who had not recovered.
  • Spinal stenosis stabilizes in about 70% of cases and worsens in 15%.

Effects on Work

Studies have found that when people stay home because of back injury, only 65% are back at work within a week. Nearly 14% are still absent at one month. If someone is on disability for more than 6 months, the chance of them returning to work is only 50%.

Low back pain accounts for significant losses in work days and dollars. In 1990, it cost the U.S. $23 billion in direct medical costs and possibly as much as $85 billion in total costs (such as lost productivity). Chronic back pain has become one of the most expensive causes of disability among workers under the age of 45. One study found that, although severe back pain comprised only 10% of workers compensation cases, it accounted for 86% of compensation costs.

Cauda Equina Syndrome

Cauda equina syndrome is the impingement of the cauda equina (the four strands of nerves leading through the lowest part of the spine). It is an emergency condition that can cause severe complications of the bowel or bladder. Cauda equina syndrome is usually caused by massive extrusion of the disk material. It can cause permanent incontinence if not promptly treated with surgery. Symptoms of the cauda equina syndrome include:

  • Dull back pain
  • Weakness or numbness in the buttocks, in the area between the legs, or in the inner thigh, backs of legs, or feet. May cause difficulty in standing or stumbling.
  • An inability to control urination and defecation
  • Pain accompanied by fever (can indicate an infection)

Warning Signs for Serious Underlying Problems

Certain warning signs should alert a patient to see a doctor immediately for low back pain. Any very severe back pain warrants attention, particularly if any of the following conditions are present:

  • Being over 50
  • Recent injury
  • Severe pain
  • Pain awakens the person at night
  • Pain accompanied by fever (possible infection)
  • Pain increased by lying down
  • Pain unrelated to movement
  • Pain lasts for a month, and is accompanied by unexplained fever or weight loss
  • History or chronic use of corticosteroids
  • Intravenous drug use
  • History of urinary tract infection
  • In children, any severe neck or back pain or pain that persists for more than 3 days
Review Date: 4/26/2006
Reviewed By: Harvey Simon, MD, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital