What is back pain?

Back pain can occur anywhere along the spine, but the most common site is the lower back or lumbar region. The lower part of the back bears the weight of the upper body plus any weight you are carrying, and it also twists and bends more than the upper back.

Back pain may be acute or chronic. Most cases of back pain are acute i.e. the pain starts suddenly and intensely, and usually lasts a short time (less than a month). Acute back pain is not usually caused by a serious medical condition, and most cases resolve within a few days without treatment. Recurrence is common, however. Repeated episodes may eventually lead to chronic back pain.

Chronic back pain persists beyond three months, and even slight movements can trigger it. Chronic pain is usually more intractable than acute pain, and often requires specialist advice.

Structure of the back

The back's system of bones, muscles, ligaments, tendons and nerves work together to bear the weight of your body and the loads you carry. The structure of the back provides considerable strength and flexibility, but because the spine is so central to the body's movements, even small amounts of damage can often cause pain.

The spine consists of 33 bony segments, the vertebrae. Between these lie the discs: tough, spongy "cushions" that act as shock absorbers for the vertebrae and give the spine flexibility. Strong elastic ligaments hold the vertebrae and discs firmly together in a column. Muscles attach to the vertebrae by fibrous connections called tendons. The complex layers of back muscle contract to move your back and upper body.

The spine also protects the spinal cord, which runs down through a canal formed by the vertebrae. Nerves from the spinal cord branch out and leave the spine through spaces between the vertebrae at the levels of the discs.

Who gets back pain and who is at risk?

Back pain is second only to headaches as the most common location of pain. Four out of five adults will experience at least one bout of back pain in their lives.

The following factors can increase your risk for back problems:

Ageing. Discs begin gradual deterioration by age 30. With age, the discs lose moisture and shrink. This puts more stress on the facet joints which become arthritic with resultant back pain.
Sedentary lifestyle. Being unfit increases your risk for back pain, especially if you attempt an unaccustomed activity. Lack of exercise leads to the following conditions, which may threaten your back:

Muscle inflexibility: read more