Over time, poor posture causes strain of the bands of muscle surrounding the spine (particularly in the curve of the lower back). Those whose job involves a lot of walking or physical labour develop good muscle tone in their backs and legs. People who sit most of the day lose that muscle tone, and their backs are the first place to show it.
The most common form of backache is lumbago, which can occur quite suddenly or develop over hours or even days. Lumbago is generally triggered by a lifting or twisting action, or may develop following an injury or over use of the back muscles.
The bones of the spine (vertebrae) are cushioned from each other by discs (pads of tissue made up of a tough, fibrous outer layer and a softer, jelly-like inner layer). A slipped disc occurs when the tough outer layer cracks open and the softer inner layer protrudes out through the crack. The disc protrusion happens where the outer layer of the disc is weakest (usually just in front of the nerve roots which emerge from the spinal cord at each vertebrae level). The painful symptoms occur when the protruding disc material presses on the nerve in the spinal column, and will sometimes also be referred to the area of the body that is supplied by that particular nerve. Most affected discs are in the lower back region.
Spinal discs can be subject to normal wear and tear and can actually wear away, removing the shock absorbing characteristics of the spine and leading to strong pain and reduced mobility. This is usually a result of normal ageing processes, but is more likely to occur in those who have experienced back injury in the past. In some cases this will develop into osteoarthritis.
Stress or tension can also create or aggravate back pain. Fibrositis is the term used to describe chronic backache resulting from localised muscle tension, which may in turn be psychosomatic in origin. In some people with depression or anxiety, backache will develop as a symptom of their mental state.
Cancer of the vertebrae is very rare, but it can spread to bones from other sites in the body. This disease is extremely serious and makes the patient feel very run down and unwell and should be confirmed by an X-ray or bone scan.
Back pain can also be due to an extensive range of other causes from pregnancy to infection and, if persistent, should always be discussed with your healthcare professional.