Lower Back Pain: Causes

What causes lower back pain?

The lower back consists of the lumbar spine (bony structures called vertebrae surrounding the nerves of the spinal cord). Between the vertebrae are spongy sacs of cartilage called disks that act as a cushion and provide a range of motion to the back. Muscles, tendons and ligaments provide additional support. Any of these structures in the back can become irritated or inflamed in response to a variety of mild to serious conditions.

A common cause of mild to severe lower back pain is often mechanical, such as a sudden movement during activities such as sports or home improvement projects. People who normally lead a relatively sedentary lifestyle are at increased risk for these types of strains and sprains. Alternatively, lower back pain can also be due to more serious conditions, such as spinal trauma, disk herniation, and spinal cancer. A problem in another part of the body, such as the reproductive organs, can also radiate to the lower back. This is called referred lower back pain.

Structural causes of lower back pain

Lower back pain can be due to injury, inflammation, or infection of the bones and tissues including:

• Herniated disk

• Muscle spasm

• Osteoarthritis

• Osteomyelitis (infection or inflammation of the spinal bones)

• Osteoporosis (metabolic bone disease)

• Paget’s disease of the bone

• Sciatic nerve damage due to spinal stenosis or degenerative disk disease

• Spinal degeneration (degenerative disk disease, also called spondylosis)

• Spinal stenosis (a narrowing of the spinal canal that presses on the spinal cord or nerves)

• Spine fracture

• Spondylitis (infection or inflammation of the spinal joints)

• Sprains and strains due to overuse or injury

Other possible causes of lower back pain

Body systems other than the neuromuscular system can lead to lower back pain, such as:

• Fibromyalgia

• Pelvic inflammatory disease

• Premenstrual syndrome

• Uterine prolapse

Life-threatening causes of lower back pain

In some cases, lower back pain may be due to a serious or life-threatening condition that should be evaluated as soon as possible or examined in an emergency setting. Possible life-threatening conditions that involve lower back pain include:

• Kidney stones and disease (including infections and tumors)

• Multiple myeloma

• Prostate cancer

• Spinal tumor or cancer (the tumor can be noncancerous, also known as benign)

What are the risk factors for lower back pain?

Although anyone can experience lower back pain, there are certain risk factors that make you more likely to encounter back pain at some point in your life. Being older than 30 years of age and leading a sedentary lifestyle are the most common. The risk factors include:

• Congenital (present at birth) or acquired back deformities (for example, scoliosis)

• Family history of back pain or spine disease

• Increasing age

• Obesity

• Poor posture

• Sedentary lifestyle

• Smoking

• Stress and anxiety

• Weak abdominal (core) muscles

What are the potential complications of lower back pain?

Lower back pain can lead to various complications depending on the underlying disease, disorder or condition. The good news is that most cases of lower back pain can be alleviated or minimized by physical therapy, basic self-care measures, and the treatment plan outlined by your doctor. However, your back pain may become chronic and overwhelming, affecting your quality of life. Research into the diagnosis and treatment of back pain is ongoing, so contact your health care professional for the latest information.

Over time, lower back pain can lead to complications including:

• Absenteeism from work or school

• Permanent nerve damage (due to a pinched nerve) including paralysis

• Physiological and psychological response to chronic pain

• Poor quality of life