The sciatic nerve is formed in the lower spine by the union of L4 to S3 1 Giuffre BA, Jeanmonod R. Anatomy, Sciatic Nerve. [Updated 2018 Dec 16]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2019 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK482431/. nerve roots and exits the pelvis through the greater sciatic foramen, below the piriformis muscle (deep in the buttock). The nerve then runs along the back of the thigh, into the leg, and ends in the foot. Sciatica occurs when this nerve is inflamed, irritated, and/or mechanically compressed at its nerve root end.
In This Article:
- The Truth About Sciatica
- The Truth About Sciatica: Genetics, Low Back Problems, Piriformis, Arthritis, and More
- Myths About Sciatica Treatment Options
- Sciatica Causes and Symptoms Video
There May be a Genetic Cause for Sciatica
Genetic factors may contribute to disc degeneration, causing sciatica.
Sciatica caused by degenerated and/or herniated discs in the lower spine may have a genetic origin. Research suggests 2 Feng Y, Egan B, Wang J. Genetic Factors in Intervertebral Disc Degeneration. Genes Dis. 2016;3(3):178–185. doi:10.1016/j.gendis.2016.04.005 , 3 Hanaei S, Abdollahzade S, Khoshnevisan A, Kepler CK, Rezaei N. Genetic aspects of intervertebral disc degeneration. Reviews in the Neurosciences. 2015;26(5). doi:10.1515/revneuro-2014-0077 that certain genetic factors are more prevalent in specific populations. These genetic defects may cause the contents of a disc to become weak and susceptible to external stress. Over time, the proteins in the disc may breakdown, compromising the integrity and function of the disc.
Herniated or degenerated discs may irritate or compress the nerve roots in the lower spine, causing sciatica.
Sciatica Is Caused by a Problem in the Lower Back
Sciatica can occur as a result of common low back conditions.
Sciatica occurs when one or more sciatic nerve roots in the lower back is irritated or compressed as it exits the spine. Each nerve root is responsible for sensory and/or motor control of a specific part of the thigh, leg, and/or foot and toes. Depending on the nerve root affected, pain and other symptoms may occur along the distribution of the nerve.
Piriformis Syndrome Feels Like Sciatica, but It isn’t the Same
The distribution of pain in sciatica and pirifromis syndrome can feel similar.
Piriformis syndrome is a condition where the piriformis muscle swells and/or develops spasms due to overuse or inflammation and irritates the sciatic nerve (which lies right below it). The nerve may also get entrapped in the muscle. Piriformis syndrome causes sciatica-like pain, tingling, and numbness that often starts from the lower back and runs down the leg and into the foot. 4 Hicks BL, Varacallo M. Piriformis Syndrome. [Updated 2018 Nov 15]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2019 Jan-.Available from: https://www.ncbi.nlm.nih.gov/books/NBK448172/.
Watch Piriformis Muscle Anatomy Animation
While the pain and discomfort from piriformis syndrome may feel similar to sciatica, it is not caused by a compressed sciatic nerve root in the spine. Piriformis syndrome pain occurs due to compression of a part of the sciatic nerve near the piriformis muscle. The pain usually follows the same pattern in the leg as a compressed sciatic nerve root.
Pain from Arthritis or Joint Problems Is not True Sciatica
SI joint arthritis can damage the joint, causing sciatica-like pain.
Arthritis or other inflammatory conditions around the hip joint may cause pain to travel down the leg similar to sciatica. This pain is usually referred down from the pain source and is not radicular nerve pain that originates from the nerve roots.
Other conditions, such as sacroiliac joint dysfunction or sacroiliitis can cause sciatica-like pain that extends down the back of the thigh but usually ends before the knee. This pain can be acute and debilitating, as in sciatica, and is caused by an abnormal motion or malalignment of the sacroiliac joint in the pelvis. 5 Raj MA, Varacallo M. Sacroiliac (SI) Joint Pain. [Updated 2019 May 12]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2019 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK470299/.
While rare, tumors, infections, or severe nerve damage in the lower spine can cause sciatica symptoms and require immediate medical attention.
In order to obtain effective pain relief from lower back and leg pain, it is important to correctly identify the exact underlying cause of sciatica. A doctor can conduct specific diagnostic and clinical tests to identify the cause and rule out serious medical conditions. Treatments for sciatica and other lower back conditions are usually different. Obtaining an accurate diagnosis can help formulate an effective treatment plan to target the specific cause.

The lower back supports the weight of the upper body and provides mobility for everyday motions, such as walking, bending, and twisting. Lower back pain may result from lumbar spine problems.
What are the common causes of chronic lower back pain?
Low back pain that lasts for more than 3 months often involves a disc problem, a joint problem, and/or an irritated nerve root. Common spine-related causes include:
- Compression Fracture
- Facet Joint Dysfunction
- Spondylolisthesis
Additional conditions include lumbar herniated disc, degenerative disc disease, sacroiliac joint dysfunction, spinal stenosis, and osteoarthritis.
What are the common symptoms associated with lower back pain?
- LOCALIZED PAIN. A dull ache or sharp pain that tends to be localized to the lower back, buttocks, and sometimes the hips.
- LEG PAIN. A sharp, electric, burning-type pain (sciatica) that may be associated with numbness or weakness and is typically felt on only one side of the body.
- POSTURE-INDUCED PAIN. Pain that worsens after prolonged sitting or standing, or after changing positions such as by bending forward, twisting, and/or lying down.
How is lower back pain treated?
Nonsurgical Treatments
A doctor may recommend one or a combination of the following nonsurgical or self-care options:
- Physical Therapy
- Ice or Heat Therapy
- Epidural Steroid
- Injections Medication
- Manual Manipulation
Surgical Treatments
Spinal surgery may be recommended in case of a medical emergency or for severe lower back pain that does not get better after 6 to 12 weeks of nonsurgical treatments.
- Microdiscectomy or Laminectomy
- Lumbar Spinal Fusion
- Artificial Disc Replacement
This information is not intended or implied as a substitute for medical advice, diagnosis or treatment. All content, including text, graphics, images or other information provided is intended for general information purposes only. Always consult with your physician for diagnosis or treatment.
- 1 Giuffre BA, Jeanmonod R. Anatomy, Sciatic Nerve. [Updated 2018 Dec 16]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2019 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK482431/.
- 2 Feng Y, Egan B, Wang J. Genetic Factors in Intervertebral Disc Degeneration. Genes Dis. 2016;3(3):178–185. doi:10.1016/j.gendis.2016.04.005
- 3 Hanaei S, Abdollahzade S, Khoshnevisan A, Kepler CK, Rezaei N. Genetic aspects of intervertebral disc degeneration. Reviews in the Neurosciences. 2015;26(5). doi:10.1515/revneuro-2014-0077
- 4 Hicks BL, Varacallo M. Piriformis Syndrome. [Updated 2018 Nov 15]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2019 Jan-.Available from: https://www.ncbi.nlm.nih.gov/books/NBK448172/.
- 5 Raj MA, Varacallo M. Sacroiliac (SI) Joint Pain. [Updated 2019 May 12]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2019 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK470299/.