Left lower back pain is a common musculoskeletal complaint. According to the National Institute of Neurological Disorders and Stroke (NINDS), a division of the National Institutes of Health (NIH), almost everyone experiences low back pain at some point in their lives. The NIH states that men and women are equally affected, and that most low back pain occurs in people aged 30 to 50 years. Low back pain can manifest in one or both sides of the spine, depending on the cause of the pain and the structures involved.
Myofascial Trigger Points
Myofascial trigger points can cause left lower back pain. According to the National Association of Myofascial Trigger Point Therapists, myofascial trigger points, or MFTPs, are a common cause of pain, including low back pain. MFTPs can form in muscle on either side of the body and are commonly found in low back muscles, such as the quadratus lumborum. MFTPs often develop in a muscle following muscle stress or injury and are hyperirritable nodules or knots that form within a tight band of muscle. When pressed, trigger points cause pain in the affected area although they can also refer or send pain to another muscle or location in the body. Common causes of MFTPs include the following: repetitive overuse injuries, heavy lifting activities, poor posture, mental or emotional stress, traumatic injury and a sedentary lifestyle.
Herniated Disc
A herniated lumbar intervertebral disc can cause left lower back pain. The American Academy of Orthopaedic Surgeons (AAOS) states that a herniated disc is a common source of pain in the lower back and legs. Lower back, or lumbar, spinal discs are made up of a thick, cartilaginous outer ring called an annulus and an inner gel-like material known as the nucleus. Most disc herniations in the lumbar spine occur in a posterolateral direction--toward the rear of the affected disc and slightly to one side or the other. If the disc herniates toward the left side of the spine, it can impinge left-sided nerve roots--offshoots of the spinal cord--and cause left-sided lower back pain and pain in the back of the thigh. According to the AAOS, there are several major risk factors for a lumbar herniated disc, including the following: improper lifting technique, smoking, excessive body weight, sudden unguarded movements and repetitive strain on the low back tissues.
Kidney Stones
Kidney stones can also cause left lower back pain. According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), a division of the National Institutes of Health, kidney stones are small, hard, crystalline masses that can move in the urinary tract and block urine flow. The NIDDK notes that most kidney stones do not cause symptoms, passing harmlessly through the urinary tract. Usually,
urine contains substances that prevent or limit crystal formation, although these substances do not appear to work in some people. According to the NIDDK, more than 5 percent of Americans have stone-forming disease. Kidney stones occur more frequently in men, and Caucasians are more likely to develop kidney stones that African Americans. Common signs and symptoms associated with kidney stones include the following: extreme back and flank pain, nausea and vomiting, and blood in the urine.
References
- National Institute of Neurological Disorders and Stroke: Low Back Pain Fact Sheet
- National Association of Myofascial Trigger Point Therapists: Myofascial Trigger Point Therapy
- American Academy of Orthopaedic Surgeons: Herniated Disk
- National Institute of Diabetes and Digestive and Kidney Diseases: Kidney Stones in Adults
