According to WebMD, the top causes of chronic lower back pain are degenerative disk disease, herniated disks and osteoporosis. The likelihood of developing these conditions is determined partially by genetics. The lower back has nociceptive fibers, which are responsible for sending pain signals to the brain. Some people have more nociceptive fibers than others, resulting in varying amounts of back pain despite leading similar lifestyles.
According to WebMD, degenerative disk disease develops when the cartilage disks between the vertebrae wear away with age. These disks act as a cushion and shock absorber for the spine. Over time, as these disks erode, more pressure is placed on the jelly-like center. A herniated disk occurs when a sudden jolt or shock results in that center bulging out and pressing on the nociceptive fibers, sending a sharp pain signal to the brain. A herniated disk can also place pressure on the nerves that run down the spinal column, hurting the area from the buttocks to the leg.
WebMD describes osteoporisis as the root cause of many conditions that lead to lower back pain. As the bones become more brittle, they can form vertebral fractures that cause chronic pain. Osteoporosis can also cause bone spurs to develop, narrowing the space around the spinal cord and putting pressure on the nerves.
Injury or overuse is one of the most common causes of lower back pain. This includes sprains and strains of ligaments and muscles, compression fractures or fractures of bones, or joint injuries to the joints between spinal bones.
Treatment for lower back problems depends on the cause. Often rest, avoiding strenuous physical activity, using hot or cold compresses and taking over-the-counter pain medications are sufficient for strains and sprains. In some cases of osteoarthritis, a joint replacement may be necessary. Herniated discs may need to be surgically removed for the person to experience significant long-term pain relief.