The causes of pain that starts in the lower back and extends through the buttocks and the back of the leg to the foot may be:
1. Slipped Disc
The most common cause is when the discs between the vertebrae in the spine bulge out and press on nearby nerves. This causes severe pain and numbness.
2. Spinal Stenosis
This is a condition in which the space in the spine narrows with age, putting pressure on the spinal cord and nerves. This causes pain and weakness in the legs when walking.
3. Spondylolisthesis
This is a condition in which a vertebra in the spine slips off the vertebra below it. This compresses the nerves and causes pain to spread to the legs.
4. Piriformis Syndrome
When the piriformis muscle in the buttock becomes tight or swollen, it presses on the sciatic nerve that runs underneath it. This is common in people who sit for long periods of time.
5. Muscle Strain
Severe swelling in the muscles that support the spine can affect nearby nerves. This can be caused by lifting too much weight and sitting incorrectly.
6. Other Causes
Rarely, spinal infections, tumors, or nerve diseases caused by diabetes can also cause pain that radiates to the legs.
When should you take it seriously?
Sudden weakness in the legs.
Loss of control over bowel movements.
Severe numbness in the legs.