The longest nerve in your body, the sciatic nerve
runs from your pelvis through your hip area and buttocks and down each
leg. It divides into the tibial and peroneal nerves at the level of your
knees. The sciatic nerve controls many of the muscles in your lower legs
and provides feeling to your thighs, legs and feet.
The term sciatica refers to pain that
radiates along the path of this nerve — from your back into your buttock
and leg. The discomfort can range from mild to incapacitating, and may be
accompanied by tingling, numbness or muscle weakness. Rather than a
disorder in and of itself sciatica is a symptom of another problem, such
as a herniated disk, that puts pressure on the nerve.
Sciatic pain usually goes away on its own in six
weeks or so. In the meantime, hot and cold packs, over-the-counter pain
relievers, and exercise or physical therapy can help ease discomfort and
speed recovery. Surgery to relieve pressure on the nerve may be an option
when symptoms don't respond to conservative treatment and pain is chronic
What are the signs and
symptoms of Sciatica?
Pain that radiates from your lower (lumbar) spine
to your buttock and down the back of your leg is the hallmark of sciatica.
You may feel the discomfort almost anywhere along the nerve pathway, but
it's especially likely to follow one of these routes:
- From your lower back to your knee
- From the mid buttock
to the outside of your calf, the top of your foot and into the space
between your last two toes
- From the inside of your calf to your inner
ankle and sole
The pain can vary widely, from a mild ache to a
sharp, burning sensation or excruciating discomfort. Sometimes it may feel
like a jolt or electric shock. Sciatic pain often starts gradually and
intensifies over time. It's likely to be worse when you sit, cough or
sneeze. Usually only one lower extremity is affected.
In addition to pain, you may also experience:
- Numbness or muscle
weakness along the nerve pathway in your leg or foot. In some
cases, you may have pain in one part of your leg and numbness in
- Tingling or a
pins-and-needles feeling. This occurs most commonly in your
toes or part of your foot.
- A loss of bladder
or bowel control. This is a sign of cauda equina syndrome, a
rare but serious condition that requires emergency care. If you
experience either of these symptoms, seek medical help immediately.
What are the causes of
Sciatica usually results from compression of a
nerve root in your lower (lumbar) spine — a condition called a
radiculopathy. By far the most common cause of this compression is a
herniated disk in your lower back. Disks are pads of cartilage that
separate the bones (vertebrae) in your spine. Each disk consists of a ring
of tough fibrous tissue (annulus fibrosis) surrounding a jelly-like centre
(nucleus pulposus). Healthy disks keep your spine flexible and act as
shock absorbers to cushion the vertebrae when you move.
But as you grow older, the disks may start to
deteriorate, becoming drier, flatter and more brittle. Eventually, the
tough, fibrous outer covering of the disk may develop tiny tears, causing
the jelly-like substance in the disk's centre to
seep out (herniation or rupture). The herniated disk then often presses on
a nerve root, causing pain — which can be excruciating — in your back, leg
or both. If the damaged disk is in the middle or lower part of your back,
you also may experience numbness, tingling or weakness in your buttock,
leg or foot.
Other conditions that may put pressure on the
sciatic nerve include:
Lumbar spinal stenosis. Your
spinal cord is a bundle of nerves that extends the length of your spine.
It's housed inside a channel (spinal canal) within the vertebrae.
Thirty-one pairs of nerves branch off from the spinal cord, providing
communication between your brain and the rest of your body. In spinal
stenosis, one or more areas in the spinal canal narrow, putting pressure
on the spinal cord or on the roots of these branching nerves. When the
narrowing occurs in the lower spine, the lumbar and sacral nerve roots
may be affected.
condition, often the result of degenerative disk disease, occurs when
one vertebra slips slightly forward over another vertebra. The displaced
bone may pinch the sciatic nerve where it leaves the spine.
Piriformis syndrome. Running
directly above the sciatic nerve, the piriformis muscle starts at your
lower spine and connects to each thighbone (femur). Piriformis syndrome
occurs when the muscle becomes tight or goes into spasms, putting
pressure on the sciatic nerve. Active women — runners and serious
walkers, for example — are especially likely to develop the condition.
Prolonged sitting, car accidents and falls also may contribute to
Spinal tumors. A tumour
is a mass of abnormal cells. In the spine, these growths may occur
inside the spinal cord, within the membranes (menninges)
that cover the spinal, or in the space between the spinal cord and the
vertebrae — the most common site. As it grows, a tumour
compresses the cord itself or the nerve roots. This can cause severe
back pain that may extend to your hips, legs or feet; muscle weakness
and a loss of sensation — especially in your legs; difficulty walking;
and sometimes loss of bladder or bowel function.
Trauma. A car accident, fall or
blow to the spine can injure the lumbar or sacral nerve roots.
Sciatic nerve tumour
or injury. Although uncommon, the sciatic nerve itself may be
affected by a tumour or injury, leading to
Other causes. In some cases, your
doctor may not be able to find a cause for your sciatica. A number of
problems can affect the bones, joints and muscles, all of which could
potentially result in sciatic pain.
To help diagnose sciatica and pinpoint which
nerves, if any, are affected, your doctor will ask about your medical
history and perform a thorough physical exam, paying special attention to
your spine and legs. You're also likely to have some basic tests that
check your muscle strength and reflexes. For example, you may be asked to
walk on your toes or heels, rise from a squatting position and, while
lying on your back, lift your legs one at a time straight in the air. Pain
that results from sciatica will usually become worse during these
If your pain lasts longer than six weeks or is
very severe, or you have another serious condition such as cancer, you may
have one or more imaging tests to help identity why the sciatic nerve is
compressed and to rule out other causes for your symptoms.
These tests include:
- Spinal X-ray.
Because ordinary X-rays can't detect herniated disk problems or nerve
damage, they're not usually helpful for pinpointing the cause of
sciatica. However, a spinal X-ray can show narrowed disks and
- Magnetic resonance
imaging (MRI). This is probably the most sensitive test for
assessing sciatic nerve pain. Instead of X-rays, MRI uses a powerful
magnet and radio waves to produce cross-sectional images of your back.
The test can detect damage to your disks and ligaments as well as the
presence of tumors. MRI is non invasive and
has no harmful side effects. During the test, you lie on a movable table
inside the MRI machine, which is essentially a large magnet. If you have
a hard time lying still for the required period of time — usually 30 to
90 minutes — or you're anxious about the enclosed space, you may be
given a sedative. Some MRI units may be wider, shorter or open on all
sides, which may be more comfortable for you, although the quality of
images taken with these systems may vary.
tomography (CT) scan. This test uses a narrow beam of radiation
to produce detailed, cross-sectional images of your body. When CT is
used to image the spine, a contrast dye may be into your spinal canal
before the X-rays are taken — a procedure called a CT myelogram. The dye
then circulates around your spinal cord and spinal nerves, which appear
white on the scan. The test can show herniated disks and tumours,
but it poses some risks, including infection and damage to the spinal
cord. In addition, CT exposes you to more ionizing radiation than do
For most people, sciatica responds well to
self-care measures. You'll heal more quickly if you continue with your
usual activities but avoid what may have triggered the pain in the first
place. Although resting for a day or so may provide some relief, prolonged
bed rest isn't a good idea. In the long run, inactivity will make your
Here are conservative measures that you can take
or that your doctor may suggest:
- Cold packs.
Initially, your doctor may suggest using cold packs to reduce
inflammation and relieve discomfort. Wrap an ice pack or a package of
frozen peas in a clean towel and apply to the painful areas for 15 to 20
minutes at least four times a day.
- Hot packs.
After 48 hours, apply heat to the areas that hurt. Use warm packs, a
heat lamp or a heating pad on the lowest setting. If you continue to
have pain, try alternating warm and cold packs.
Initially, passive stretching exercises can help you feel better and may
relieve compression, but avoid jerking, bouncing or twisting.
medications. Pain relievers (analgesics) fall into two
categories — those that reduce pain and inflammation and those that only
treat pain. Non steroidal anti-inflammatory
drugs (NSAIDs) such as aspirin and ibuprofen which help alleviate both
discomfort and inflammation, are the most helpful for sciatica. Although
they can provide real relief, NSAIDs have a "ceiling effect" — that is,
there's a limit to how much pain they can control. If you have moderate
to severe pain, exceeding the recommended dosage won't provide
additional benefits. What's more, NSAIDS can cause side effects such as
nausea, stomach bleeding or ulcers. If you take these medications, talk
to your doctor so that you can be monitored for problems. In addition,
periodically re-evaluate whether you still need NSAIDs. Exercise,
stretching, massage and other non drug
treatments can often provide the same benefits without side effects.
- Prescription drugs.
In some cases, your doctor may prescribe an anti-inflammatory medication
along with a muscle relaxant. Tricyclic antidepressants, such as
nortriptyline or amitriptyline and anticonvulsant drugs, such as
gabapentin, also may be prescribed for chronic pain. They may help by
blocking pain messages to the brain or by enhancing the production of
endorphins, your body's natural painkillers.
- Physical therapy.
If you have a herniated disk, physical therapy can play a vital role in
your recovery. Once acute pain improves, your doctor or a physical
therapist can design a rehabilitation program to help prevent recurrent
injuries. Rehabilitation typically includes exercises to help correct
your posture, strengthen the muscles supporting your back and improve
your flexibility. Your doctor will have you start physical therapy,
exercise or both as early as possible. It's the cornerstone of your
treatment program and should become part of your permanent routine at
- Regular exercise.
It may seem counterintuitive to exercise when you're in pain, but the
fact is that regular exercise is one of the best ways to combat chronic
discomfort. Exercise prompts your body to release endorphins — chemicals
that prevent pain signals from reaching your brain. Endorphins also help
alleviate anxiety and depression, conditions that can make your pain
more difficult to control. What's more, combining aerobics with strength
training and exercises that maintain or improve flexibility can help
prevent age-related degenerative changes in your back. If you're new to
exercise, start out slowly and progress to at least 30 minutes most
days. To prevent injury, consider learning proper weight lifting
techniques from a certified personal trainer, fitness specialist or
Complementary and alternative medicine (CAM)
refers to medical and health care systems, practices and products that
aren't currently part of conventional medicine — the care you receive in
your primary care doctor's office. Many of these therapies are being
studied intensely and some have proven to help alleviate back pain.
Originating in China more than 2,500 years ago, this medical system is
based on the idea that that health and life depend on a vital energy
called qi — pronounced "chee" and sometimes written chi — that is
believed to flow along 14 pathways in your body. When qi is blocked,
disease and pain result. Inserting very fine needles into specific
points along the meridians is designed to unblock energy flow and
restores your body's healthy balance. During an acupuncture treatment,
you're likely to have from one to 20 or more hair-thin needles inserted
into your skin. Most needles are inserted superficially, although some
may go deeper, depending on where they're placed and the problem being
treated. In most cases, you won't feel the needles — in fact, many
people find the treatments extremely relaxing. The needles may remain in
place from a few minutes to half an hour or longer.
Magnetic therapy. The application of static high strength rare earth
magnets at the point of pain over a period of time. Available in many
forms such as
magnetic straps/ wraps, pillows,
jewellery, mattress covers and water.
This therapy is based on the same principles as acupuncture, but rather
than using needles, the practitioner massages or presses specific points
along the meridians to effect healing. Although the results may be more
subtle than with acupuncture, acupressure may be a good choice if you'd
rather avoid needles.
Chiropractic treatment is based on the philosophy that restricted
movement in the spine may lead to reduced function and pain. Spinal
adjustment (manipulation) is one form of therapy chiropractors use to
treat restricted spinal mobility. The goal is to restore spinal movement
and, as a result, improve function and decrease pain.
People have been using hypnosis to promote healing since ancient times.
In the past 50 years, however, it's experienced a resurgence among
physicians, psychologists and mental health professionals. Hypnosis
produces an induced state of deep relaxation in which your mind stays
narrowly focused and open to suggestion. During hypnosis, you can
receive suggestions designed to decrease your perception of pain and
increase your ability to cope with it. It also can help you stop habits
such as smoking. No one knows exactly how hypnosis works, but experts
believe it alters your brain wave patterns in much the same way as other