The most common cause of back pain is injury to the ligaments supporting the spine. The pain typically clears up on its own after a short period. If lying down and resting the muscles don’t relieve the pain, or your back pain is accompanied by numbness or pain in other areas of your body, you should consult an expert. Severe back pain may be caused be a problem affecting the spine or spinal nerves, such as fractured vertebrae, herniated spinal disc or spinal cord. Kidney problems such as a kidney stone can cause severe back pain. Severe back pain should be checked by a medical professional.