Causes of Sciatica

Proper treatment of sciatica requires both treating the immediate symptoms as well as treating the underlying cause of the condition. However, with how many medical issues can cause sciatica, finding the underlying cause is not always an easy task.

Six of the Most Common Causes of Sciatica

  1. Degenerative Disc Disease – Disc degeneration is a natural process that occurs over time as we age.  When this degeneration becomes excessive, it can cause the lower back to irritate a nerve root, in turn leading to sciatica.

Diagnosis of this condition occurs by recognizing excessive micromotion at a particular part of the spine where the condition exists. This motion causes inflammatory proteins from within the disc to become exposed. The proteins irritate the nerve roots in that particular area, leading to the sciatica.

  1. Lumbar Herniated Disc – Also known as a slipped disc, bulging disc, ruptured disc, pinched nerve, or protruding disc. A herniated disc arises when the disc’s soft, inner material leaks out.  As this material seeps through the fibrous outer core of the disc, it pinches or irritates the nerve root. A lumbar herniated disc is almost always associated with sciatica.


  1. Sacroiliac Joint Dysfunction – The sacroiliac joint is located at the very bottom of the spine.  Irritation of this joint can in turn irritate the nerve that lies on top of the sacroiliac joint, the L5 nerve. When it does so, it will cause sciatica-like symptoms.  


  1. Isthmic Spondylolisthesis – This is a condition where a small stress fracture lets one vertebrae to slip on another.  When a combination occurs where there is a disc space collapse along with the fracture and slipping, the nerve can get pinched, resulting in sciatica.


  1. Piriformis Syndrome – Sometimes, the sciatic nerve becomes irritated as it runs underneath the piriformis muscle found in the glutes. When this muscle pinches or otherwise irritates a nerve root of the sciatic nerve, it can induce sciatica-like pain. While this condition is not technically sciatica, since the leg pain feels the same as sciatica, it is oftentimes referred to as sciatica for simplicity.


  1. Lumbar Spinal Stenosis – Lumbar spinal stenosis is directly related to the natural aging process of the spine. It is fairly common in adults over 60. The resulting narrowing of the spinal canal from this condition can lead to sciatica. It is a result of a combination of at least one or more of the following:


    • Overgrowth of soft tissue
    • Bulging disc putting pressure on the nerve roots
    • Enlarged facet joints

Additional Causes of Sciatica and Similar Symptoms

While not as common as the aforementioned causes, additional causes of sciatica-type pain include:

  • Pregnancy
  • Muscle Strain
  • Spinal Tumor
  • Scar Tissue
  • Fracture
  • Infection
  • Ankylosing Spondylitis

In addition, research has shown that those who are obese or smoke have an increased risk of developing sciatica. Since any form of nicotine causes disc degeneration, essentially any form of tobacco use will increase one’s risk.

Depending on the specific root cause of the condition, treatment can vary greatly. Specific exercises to treat the sciatica will almost always be a part of the regimen, but since the causes of sciatica vary so greatly, until one finds the root cause, it is difficult to say what the optimal treatment would be for their particular condition.