The term sciatica describes the symptoms of leg pain—and possibly tingling, numbness or weakness—that originate in the lower back and travel through the buttock and down the large sciatic nerve in the back of the leg.
Sciatica (pronounced sigh-at-ih-kah) is not a medical diagnosis in and of itself—it is a symptom of an underlying medical condition, such as a lumbar herniated disc, degenerative disc disease, or spinal stenosis.
Sciatica Nerve Pain
Sciatica is often characterized by one or a combination of the following symptoms:
- Constant pain in only one side of the buttock or leg (rarely can occur in both legs)
- Pain that is worse when sitting
- Leg pain that is often described as burning, tingling or searing (vs. a dull ache)
- Weakness, numbness or difficulty moving the leg or foot
- A sharp pain that may make it difficult to stand up or to walk
Sciatic pain can vary from infrequent and irritating to constant and incapacitating. Specific sciatica symptoms can be different in location and severity, depending upon the condition causing the sciatica (such as a lumbar herniated disc ).
While symptoms can be painful and potentially debilitating, it is rare that permanent sciatic nerve damage (tissue damage) will result.
The Sciatic Nerve and Sciatica
Sciatica symptoms occur when the large sciatic nerve is irritated or compressed in the lumbar spine.
The sciatic nerve is the largest single nerve in the body and is composed of individual nerve roots that start by branching out from the spine in the lower back and combine to form the “sciatic nerve.”
- The sciatic nerve starts in the lower back at lumbar segment 3 (L3).
- At each level of the lower spine a nerve root exits from the inside of the spine, and these respective nerve roots then come together to form the large sciatic nerve.
- The sciatic nerve runs from the lower back, through the buttock, and down the back of each leg
- Portions of the sciatic nerve then branch out in each leg to innervate certain parts of the leg – the thigh, calf, foot, toes.
The specific sciatica symptoms – the leg pain, numbness, tingling, weakness, and possibly symptoms that radiate into the foot – largely depend on where the nerve is pinched. For example, a lumbar segment 5 (L5) nerve impingement can cause weakness in extension of the big toe and potentially in the ankle.
The Course of Sciatica Pain
The incidence of sciatica increases in middle age. Rarely occurring before age 20, the probability of experiencing sciatic pain peaks in the 50s and then declines.1
Often, a particular event or injury does not cause sciatica, but rather it tends to develop over time.
The vast majority of people who experience sciatica get better within a few weeks or months and find pain relief with non-surgical sciatica treatment. For others, however, the leg pain from a pinched nerve can be severe and debilitating.
There are a few symptoms that may require immediate medical, and possibly surgical, intervention, such as progressive neurological symptoms (e.g. leg weakness) and/or bowel or bladder dysfunction (Cauda Equina Syndrome).
Because sciatica is caused by an underlying medical condition, treatment is focused on addressing the underlying causes of symptoms, such as spinal stenosis or a herniated disc. Treatment is usually self-care and/or non-surgical, but for severe or intractable pain and dysfunction it may be advisable to consider surgery.
When discussing sciatica it is important to understand the underlying medical cause of the sciatica symptoms, as effective treatment will focus on addressing the root cause of the pain.
6 most common causes of sciatica
There are 6 lower back problems that are the most common causes of sciatica:
Lumbar herniated disc: A herniated disc occurs when the soft inner core of the disc (nucleus pulposus) leaks out, or herniates, through the fibrous outer core (annulus) and irritates the contiguous nerve root. A herniated disc is sometimes referred to as a slipped disc, ruptured disc, bulging disc, protruding disc, or a pinched nerve. Sciatica is the most common symptom of a lumbar herniated disc.
Degenerative disc disease: While disc degeneration is a natural process that occurs with aging, for some people one or more degenerated discs in the lower back can also irritate a nerve root and cause sciatica. Degenerative disc disease is diagnosed when a weakened disc results in excessive micro-motion at that spinal level, and inflammatory proteins from inside the disc become exposed and irritate the nerve root(s) in the area.
Isthmic spondylolisthesis: This condition occurs when a small stress fracture allows one vertebral body to slip forward on another; for example, if the the L5 vertebra slips forward over the S1 vertebra. With a combination of disc space collapse, the fracture, and the vertebral body slipping forward, the nerve can get pinched and cause sciatica.
Lumbar spinal stenosis: This condition commonly causes sciatica due to a narrowing of the spinal canal. Lumbar spinal stenosis is related to natural aging in the spine and is relatively common in adults over age 60. The condition typically results from a combination of one or more of the following: enlarged facet joints, overgrowth of soft tissue, and a bulging disc placing pressure on the nerve roots, causing sciatica pain.
Piriformis syndrome: The sciatic nerve can get irritated as it runs under the piriformis muscle in the buttock. If the piriformis muscle irritates or pinches a nerve root that comprises the sciatic nerve, it can cause sciatica-type pain. This is not a true radiculopathy (the clinical definition of sciatica), but the leg pain can feel the same as sciatica caused by a nerve irritation.
Sacroiliac joint dysfunction: Irritation of the sacroiliac joint—located at the bottom of the spine—can also irritate the L5 nerve, which lies on top of the sacroiliac joint, causing sciatica-type pain. The leg pain can feel the same as sciatica caused by a nerve irritation.
More causes of sciatica
In addition to the most common causes, a number of other conditions can cause sciatica, including:
- Pregnancy. The changes that the body goes through during pregnancy, including weight gain, a shift on one’s center of gravity, and hormonal changes, can cause sciatica during pregnancy.
- Scar tissue. If scar tissue compresses the nerve root, it can cause sciatica.
- Muscle strain. In some cases, inflammation related to a muscle strain can put pressure on a nerve root and cause sciatica.
- Spinal tumor. In rare cases, a spinal tumor can impinge on a nerve root in the lower back and cause sciatica symptoms.
- Infection. While rare, an infection that occurs in the low back can affect the nerve root and cause sciatica.
It is important to know the underlying clinical diagnosis of the cause of sciatica, as treatments will often differ depending on the cause. For example, specific sciatica exercises, which are almost always a part of a treatment program, will be different depending on the underlying cause of the symptoms.
Do you suffer from Sciatica? Call our office today at (304) 263-4927 to schedule an appointment. Dr Terry Chambers is a Board certified chiropractor and acupuncturist, licensed in WV, and trained to perform functional medicine.