Back pain in general is the second most common, with headache ranking as first, neurological disorder in the U.S., according to the National Institute of Neurologic Disorders and Stroke. Pain felt specifically in the lower left quadrant of the back can occur due to disorders and injuries of the back, or due to disorders and diseases of organs that reside in the abdominal cavity.
Diverticulitits
The colon, also known as the large intestine, can contain small pouches in the lining that bulge out in weak spots. The presence of these pouches, called diverticulum, results in a condition known as diverticulosis. Diverticulosis, a common condition affecting approximately half of all people older than age 60, produces few symptoms, according to the National Digestive Diseases Information Clearinghouse. When the pouches become infected; however, the condition---known as diverticulitis---worsens, causing severe abdominal pain in the lower left side. The abdominal pain can radiate to the back, resulting in pain in the lower left quadrant.
Kidney Stones
The kidneys, two bean-shaped organs located under the rib cage, filter waste products and excess water from the blood. The waste and excess water form urine that flows to the bladder through tubes known as ureters. Kidney stones form when substances in the urine crystallize. Tiny stones move through the urinary tract unnoticed. Larger stones can become lodged in the ureters and block the flow of urine. This causes extreme pain felt in the lower abdomen and the lower back, on the side of the stone. A kidney stone originating in the left kidney, for example, causes pain in the lower left quadrant of the back.
Facet Joint Strain
The back contains a complex structure of bones, muscles and other tissue that function together to provide the body support and flexibility while protecting the spinal cord. The spine consists of 24 vertebrae stacked on top of each other. Each vertebra connects to other vertebrae at joints known as facet joints. The facet joints allow the vertebrae to move against each other and provide the flexibility to bend forward, backward and side to side, as described by the Cleveland Clinic.
When a facet joint becomes strained, due to injury caused by lifting or overstretching, the muscles surrounding the spine tighten to protect the joint. Depending on the area of the strain, the muscle spasms can cause pain in the lower left quadrant of the back.
Herniated Disc
A soft jelly-like pad, known as an intervertebral disc, sits between each vertebra, providing cushion and acting as a shock absorber. Injury to the back caused by severe strain or compression can cause an intervertebral disc to rupture, or bulge, known as a herniated disc. The bulging disc may put pressure on one of the more than 50 nerves rooted in the spinal cord, according to the National Institute of Neurologic Disorders and Stroke. A compressed nerve results in lower back pain felt on either the right or left side, depending on the nerve compressed, that can radiate down the leg causing numbness and weakness.
References
- National Institute of Neurologic Disorders and Stroke: Low Back Pain
- National Digestive Diseases Information Clearinghouse: Diverticulosis and Diverticulitis
- National Kidney and Urologic Diseases Information Clearinghouse: Kidney Stones
- The Cleveland Clinic: Structure and Function of a Healthy Spine
- American Academy of Orthopedic Surgeons: Herniated Disc
