This is a three-part series on the sciatic nerve. It will include a brief overview of the sciatic nerve anatomy and physiology, causes of sciatic nerve pain (sciatica), and treatments for sciatica.
by: Dr. David Futral
As mentioned in the previous post, the sciatic nerve is the largest nerve in the human body. As such, it can be irritated, inflamed, or compressed frequently causing severe pain, numbness, tingling, and/or weakness in the lower extremity. Below are some of the more common causes of sciatica.
Disc problems: disc problems tend to be one of the most common causes of sciatica. I say disc problems because that can be inclusive of disc: herniations, bulges, and protrusions. Each of these is classified differently based on radiographic evidence but can all cause sciatic nerve pain. (Refer to our page later for a classification of disc problems.)
Another cause of sciatic nerve pain is degenerative arthritis. This condition is when the vertebrae grow bone spurs that impinge, irritate, or compress the nerve. As the branches of the sciatica nerve exit between the vertebrae, the hole they exit (called a foramen) can decrease in size due to bone spur formation thereby causing sciatic nerve pain. This narrowing of the foramen is called foraminal stenosis.
Muscle spasms can also cause entrapment of the sciatic nerve. Muscles in the gluteal region, specifically the piriformis muscle, can spasm as the nerve traverses through the belly of the muscle and cause irritation leading to sciatic nerve pain.
Two of the more uncommon causes of sciatic nerve pain are 1) pregnancy and 2) spondylolisthesis. Pregnancy related sciatica occurs as the patient’s body changes with the growth of the baby and those changes can cause irritation to the sciatic nerve. Spondylolisthesis is when one vertebrae slides anteriorly (forward) on with respect to the vertebrae below it. If this occurs, the narrowing of the foramen can accompany the slippage and cause irritation of the nerve.
To summarize, there are several conditions that can cause sciatic nerve pain. It is important that you are properly examined by a medical professional to determine the cause of the condition so you can receive the proper treatment.
Yours in health,
Dr. David Futral