Sciatica is the name given to pain caused by irritation of the sciatic nerve. Anything that irritates this nerve can cause pain, ranging from mild to severe. Sciatica is usually caused by a compressed nerve in the lower spine.
Often, the term “sciatica” is confused with general back pain. However, sciatica is not just limited to the back. The sciatic nerve is the longest and widest nerve in the human body. It runs from the lower back, through the buttocks, and down the legs, ending just below the knee.
This nerve controls several muscles in the lower legs and supplies sensation to the skin of the foot and the majority of the lower leg. Sciatica is not a condition, but rather a symptom of another problem involving the sciatic nerve. Some experts estimate that up to 40 percent of people will experience sciatica at least once in their life.
Risk factors for sciatic nerve pain
Common risk factors include:
- Age – people in their 30s and 40s have a higher risk of developing sciatica.
- Profession – jobs that require lifting heavy loads for long periods.
Sedentary lifestyle – people who sit for long periods and are physically inactive are more likely to develop sciatica, compared with active people.
Symptoms of sciatica
The main symptom is a shooting pain anywhere along the sciatic nerve; from the lower back, through the buttock, and down the back of either leg.
Other common symptoms of sciatica include:
- numbness in the leg along the nerve
- tingling sensation (pins and needles) in the feet and toes
This pain can range in severity and may be aggravated by sitting for long periods.
Causes of sciatica
Sciatica is a common symptom of several different medical conditions; however, an estimated 90 percent of cases are due to a herniated (slipped) disk. The spinal column is made up of three parts:
- vertebra (individual bones in the spine that protect underlying nerves)
- nerves
- disks
Disks are made of cartilage, which is a strong and resilient material; the cartilage acts as a cushion between each vertebra and allows the spine to be flexible. A herniated disk occurs when a disk is pushed out of place, putting pressure on the sciatic nerve.
Other causes of sciatica include:
- Lumbar spinal stenosis – narrowing of the spinal cord in the lower back.
- Spondylolisthesis – a condition where a disk slips forward over the vertebra below it.
- Tumors within the spine – these may compress the root of the sciatic nerve.
- Infection – ultimately affecting the spine.
- Other causes – for instance, injury within the spine.
- Cauda equina syndrome – a rare but serious condition that affects the nerves in the lower part of the spinal cord; it requires immediate medical attention.
In many cases of sciatica, there is no single obvious cause.
How is sciatica diagnosed?
If the symptoms of sciatica are mild and do not last longer than 4-8 weeks, it is probably acute sciatica, and medical attention is not usually necessary.
A complete medical history may help speed up the diagnosis. Doctors will also have the individual perform basic exercises that stretch the sciatic nerve. A shooting pain down the leg while performing these exercises usually indicates sciatica.
If pain persists for more than 4-8 weeks, imaging tests such as an X-ray or MRI may be necessary to help identify what is compressing the sciatic nerve and causing the symptoms.
What are the treatments for sciatica?
We will look at treatments for acute and chronic sciatica individually:
Acute sciatica treatments
Most cases of acute sciatica respond well to self-care measures, which include:
- Over-the-counter painkillers such as ibuprofen.
- Exercises such as walking or light stretching.
- Hot or cold compression packs help to reduce pain. It is often helpful to alternate between the two.
Not all painkillers are suitable for everyone; individuals should be sure to review options with their doctor.
Chronic sciatica treatments
Treatment of chronic sciatica usually involves a combination of self-care measures and medical treatment:
- physical therapy
- cognitive behavioral therapy (CBT) – helps manage chronic pain by training people to react differently to their pain
- painkillers
Surgery may be an option if symptoms have not responded to other treatments and continue to intensify. Surgical options include:
- Lumbar laminectomy – widening of the spinal cord in the lower back to reduce pressure on the nerves.
- Discectomy – partial or entire removal of a herniated disk.
Depending on the cause of sciatica, a surgeon will go over the risks and benefits of surgery and be able to suggest a suitable surgical option.
Exercises and stretches
There are many ways to relieve the pressure on the sciatic nerve through exercise. This allows patients to:
- alleviate their symptoms on their own
- reduce or avoid taking medications where possible
- find longer term comfort and relief for their condition during flare-ups
Pregnancy
Although sciatica-like pain can be a problem during pregnancy; an estimated 50–80 percent of women have back pain during pregnancy. Hormones produced during pregnancy, such as relaxing, cause ligaments to loosen up and stretch, which can potentially cause back pain in some women.
However, sciatica due to a herniated disk is no more likely during pregnancy.
Outlook
In most cases, sciatica will go away on its own; in the vast majority of cases, surgery is not needed. Around half of people will recover within 6 weeks.
Prevention of sciatica
In some cases, sciatica can be prevented; there are several lifestyle changes that can reduce the chances of developing it, including regular exercise and making sure proper posture is used when standing, sitting upright, and lifting objects.