The majority of low back discomfort is caused by an injury, such as muscular sprains or strains caused by rapid movements or poor body mechanics while lifting heavy goods. Low back discomfort can also be caused by certain disorders, such as spinal cord malignancy. A herniated or ruptured disc can also cause pain to radiate down one leg. Aging bodies are also susceptible to low back pain due to the increased stress on the discs as we age; these problems are especially common in people who suffer from arthritis. Pain that radiates down one leg and foot and cannot be relieved by lying down may be caused by a blood clot or tumor in the leg. This type of pain is often severe and may keep you from sleeping at night. See your doctor if you experience pain like this so that it can be treated promptly. Low back pain is one of the most common reasons for visiting a physician. It's estimated that 80 percent of people will experience low back pain at some time in their lives. However, only 15 percent of those people seek medical care for their problem. The reason many people don't see a doctor when they first experience low back pain is because there are many other things that can cause pain or trouble walking, like diabetes or heart disease. But if you have low back pain for more than three months or if it gets worse with time, then you should see a doctor to make sure that you aren't developing any problems.