Acute back pain is commonly caused by injury, although simply slouching or sitting at a desk for long periods can also contribute.
Sprains or strains from overstretching or tearing of ligaments, tendons, or muscles account for most back pain episodes.
In addition, as people get older they may experience degeneration of the spine caused by normal wear and tear on joints and vertebrae that support the back.
Both normal aging and injuries can lead to deterioration of the discs that cushion the vertebrae. As a result, the normally rubbery discs lose their integrity and no longer provide the cushioning the spine needs.
When a disk ruptures or herniates, the resulting compression of the vertebrae can impinge upon the nerve roots and cause excruciating pain.
Compression, inflammation, or injury can also irritate the root of the spinal nerves between the vertebrae, leading to radiculopathy, a compressed nerve that causes pain, numbness, and tingling that can radiate to other parts of the body, particularly the hips, buttocks, legs, and feet.
One common form of radiculopathy is sciatica, which results from compression of the sciatic nerve in the lower back. When severe, the pinched nerve causes not only pain and numbness, but muscle weakness as well.
Spinal stenosis is another source of back pain. This condition is the result of narrowing in the spinal column which leads to pressure on the nerves.
Other people suffer from scoliosis, a curvature of the spine that often leads to pain in the lower back.