Sciatica is the pain caused by irritation of the sciatic nerve the longest and the widest nerve in the human body. It is a symptom of other problems involving the sciatic nerve and not a condition by itself.

The affected nerve runs from the lower back through the person’s buttocks, ending just below the knee. It controls the lower leg muscles and provides sensation to the skin of the foot and most of the lower leg. Any irritation to this nerve can cause mild to severe pain.

Causes

The pain associated with Sciatica is caused when the root of the lower lumbar and lumbosacral spine is affected.

  • Herniated (slipped) disk — Almost 90 percent of cases suffering from sciatica are associated with this condition where the cartilage between the vertebrae is temporarily moved, affecting the sciatic nerve.
  • Lumbar spinal stenosis — This is a condition where the spinal canal narrows and compresses the spinal cord, putting pressure on the sciatic nerve.
  • Spondylolisthesis — Here, one vertebra slips forward over the other, possibly affecting the nerve.
  • Spinal infections or injuries
  • Pregnancy
  • Cauda equina syndrome — This is a rare condition where the nerves in the lower part of the spinal cord are affected. It can lead to permanent nerve damage and even paralysis.

Symptoms

In most cases, sciatica only affects one side of the lower body. The pain can extend from the lower back down through the leg, continuing to the foot in some cases.

  • Severe lower back pain
  • Pain in the buttocks or leg
  • Burning sensation in the leg
  • Numbness in parts of the leg or foot
  • Tingling sensation (pins and needles) in the feet and toes

The pain can range from mild to a severe debilitating one that can affect a person’s day-to-day activities. Even for those who do not face the more painful episodes, there is a chance of the discomfort escalating.