Introduction

Back pain is one of the most common reasons people visit their doctor. According to the National Institute of Arthritis and Musculoskeletal and Skin Diseases, 25% of adults experience at least a day of back pain in a three month period.

Back pain can be acute, subacute, or chronic.

• Acute back pain develops suddenly and lasts up to several weeks. Acute pain is the most common type of back pain.
• Subacute back pain is pain that lasts up to 3 months.
• Chronic back pain can begin abruptly or gradually, but it lasts longer than 3 months.

Back pain can occur in any area of the back, but it most often strikes the lower back, which supports most of the body's weight.

The Spine

The back is highly complex, and pain may result from damage or injury to any of its various bones, nerves, muscles, ligaments, and other structures. Still, despite sophisticated techniques, which provide detailed anatomical images of the spine and other tissues, the cause of most cases of back pain remains unknown.

Vertebrae. The spine is a column of small bones, or vertebrae, that support the entire upper body. The column is grouped into three sections:

• The cervical (C) vertebrae are the seven spinal bones that support the neck.
• The thoracic (T) vertebrae are the twelve spinal bones that connect to the rib cage.
• The lumbar (L) vertebrae are the five lowest and largest bones of the spinal column. Most of the body's weight and stress falls on the lumbar vertebrae.

Click the icon to see an image of the spine.

Below the lumbar region is the sacrum, a shield-shaped bony structure that connects with the pelvis at the sacroiliac joints.

At the end of the sacrum are two to four tiny, partially fused vertebrae known as the coccyx, or "tail bone."

Click the icon to see an image of the sacrum.

• < Page
1 2
• >

Review Date: 04/07/2010
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)