What is Sciatica?
Sciatica is characterized by low back pain which radiates through the hips and buttocks and down one or both legs. It is most often caused by a disc in the spine pressing on the root of the sciatic nerve.
The sciatic nerve is responsible for controlling the muscles in the lower leg and back of the knee. It also transmits signals affecting feeling in the back, thighs, lower legs and the soles of the feet. (1)
This condition is thought to affect just under three percent of the general population annually. (2)
The main cause of sciatica is a slipped disc. The spine is made up of bones called vertebrae. In between them are discs which are soft and filled with a substance resembling jelly.
The role of the discs is to cushion the vertebrae and help keep them in place. With age the discs degenerate and lose their ability to cushion the spine. This can cause them to bulge into the vertebral canal (prolapse).
Injury can also result in herniated discs, the disk bulging beyond its limits. When this happens it can press on the sciatic nerve.
There are also occasions when the disc may rupture or break. If this happens then the jelly like substance leaks out of the center of the disc irritating the nerves.
Further factors which affect the sciatic nerve are narrowing of the space where the nerve is located, often caused by arthritis or injury, or pinching of the nerve between the spinal column and the vertebrae.
While rare, a blood clot, growth or abscess might put pressure on the sciatic nerve. (3)
The sciatic nerve runs from the base of the spinal column through the buttocks to the hips. It runs the length of each leg through to the feet and it is the largest nerve in the body. (4)
When the sciatic nerve is injured, pinched or compressed in this way, symptoms might be experienced. These include:
The pain associated with this condition can be sudden and sharp. On the other hand it can develop slowly causing a dull ache in the lower back. This pain often radiates from the lower back, through the buttocks and down the legs.
People often find this back pain is exacerbated by coughing, sneezing and moving around. The pain will generally feel worse in the buttocks and legs than in the lower back. (5)
Pressure on the sciatic nerve can cause feelings of numbness in the buttocks, legs or feet.
The numbness can be total or partial and sometimes can cause paralysis of the affected limb or foot. Paralysis is a sign the condition is serious and the nerves might be damaged. (6)
A tingling or burning sensation might also be felt down the the legs. (7)
Sciatica can feel like muscle cramps in the legs or buttocks. These can range from mild to excruciating and might last for weeks before going away. (8)
Accompanying the other symptoms, a feeling of weakness in the affected leg is also possible. (9)
Bowel and Bladder Function
If the function of your bowels or bladder becomes impaired, immediate medical attention is necessary. It could be a sign of a medical emergency called cauda equina syndrome. (10)
There are no stages associated with this condition. There are however three different categories of slipped discs, based on severity.
A prolapse is defined as an instance when a specific body part, in this case a lumbar disc, slips or moves from its normal position. (11)
While the disc bulges away from the space between the vertebrae, the outer coating or layer is not compromised. (12)
This happens when the outermost layer of a disc tears allowing tissue to spill out. The tissue which exits the disc is still connected. (13)
Tissue from a extruded disc becomes detached and enters the spinal canal. (14)
There are also factors which can predispose a person to the likelihood of experiencing sciatica. These include:
Personal Risk Factors
As we age the discs degenerate and are more likely to suffer damage. Ages most at risk are between 45 and 64 years.
Due to normal wear and tear as we get older discs lose elasticity and fluid can leak from them. As a result they become brittle and dry and no longer function to cushion the vertebrae.
Being overweight or very tall is also likely to predispose someone to this condition.
Further factors include being inactive, smoking and suffering mental stress. (15, 16)
Occupational Risk Factors
Carrying out strenuous activity which involves lifting heavy objects, twisting or bending can exacerbate the chances of developing sciatica. Jobs which involve operating or driving machinery that vibrates can also contribute to this condition. (17)
Sciatica will often get better with treatments you can carry out yourself at home.
Initially, the pain might be quite intense and you might feel the need to rest. However getting moving again as soon as possible is a good idea. As soon as you feel able, doing some gentle exercise will speed recovery.
This could include some gentle stretching or walking. Increase your activity levels at a pace which you are able to achieve.
Over the counter painkillers such as paracetamol and ibuprofen can relieve pain. Taking both regularly as directed, and not just at times when pain is felt, will help you keep on the move.
Your pharmacist will be able to help and advise you about suitable painkillers and dosage. (18)
If the pain does not ease through self help, or it gets worse, a visit to a doctor is advisable.
There are various treatments that will be considered depending on the cause and severity of the sciatica. These include:
If your doctor feels it is necessary, they may prescribe medications to reduce inflammation and relieve pain. These might include non steroidal anti inflammatories (NSAIDs), tramadol, codeine or morphine.
They might also administer steroid injections or prescribe muscle relaxants. (19, 20)
This type of therapy involves stretching and exercises aimed to build strength and restore movement. Through massage and manipulation this treatment can help relieve stiffness and pain, improve the circulation of blood and help fluid drain from the body. It might also help relaxation.
A physical therapist might also use acupuncture to deal with pain and help promote recovery.
Other options they might choose are the use of either electric current or sound waves. Electric current administered via a specialised machine can relieve pain.
Sound waves delivered via an ultrasound machine help stimulate circulation to reduce pain and muscle spasms. This also helps promote healing. (21, 22)
When sciatica doesn’t respond to non invasive treatment a referral to a neurosurgeon might be considered. This will generally only be when pain has lasted for more than three months and is not improving.
The offending disc will be removed under local, spinal or general anesthetic. (23)
What is sciatica? Sciatica is characterized by low back pain radiating through the hips and buttocks, then down one or both legs. It is most often caused by a disc in the spine pressing on the root of the sciatic nerve.
What are the signs of sciatica? Pain in the lower back which radiates down the legs through the buttocks is a sign of this condition. Tingling, numbness, cramps and burning might also be felt.
How do you develop sciatica? Sciatica is most often caused by a disc pressing on the sciatic nerve. This could be as a result of aging, obesity, injury, being inactive or social stress. Some occupations might also contribute to the onset of this condition.
How are you diagnosed for sciatica? A doctor will take a full medical history and carry out a physical examination. They may do a test call leg raising. This involves the legs being lifted while lying down until pain is felt. They may also test your reflexes. If a cause cannot be ascertained then imaging tests such as CT or MRI scans can be done. (24)
What is the best treatment for sciatica? There are treatment regimes which can be followed at home. These include rest, followed by exercise and over the counter painkillers. If this is not successful a doctor can prescribe other medications or refer an individual for surgery.
What are the long term complications of sciatica? The symptoms of this condition usually subside of their own accord in about 90 percent of people. For the remaining 10 percent, recurrence or long term pain is possible. (25)
Is sciatica considered a disability? Sciatica is not considered a disability. There are occasions when social security benefits might be paid depending on medical evidence.
Is there a cure for sciatica? In the majority of cases prognosis for this condition is good and it can be treated.
Is sciatica life threatening? This condition is not considered life threatening. However, if it interferes with the function of the bowel and bladder, it is a medical emergency. (26)
Sciatica can be a painful and, in the short term, incapacitating condition. Generally caused by a slipped disc, in the majority of cases it resolves within about six weeks.
The good news is there are treatments, whether over the counter or prescribed, that alleviate the symptoms while the body heals.