Sciatica refers to nerve pain felt from the lower back through the buttocks and down the back of the leg (where the sciatic nerve is located). One sciatic nerve runs along each side of the body, which means sciatic pain can occur from the lower spine down to either leg, depending on which sciatic nerve is affected.
Symptoms of Sciatica
- The most common and characteristic symptom of sciatica is pain that radiates from the lumbar region down the back of the leg. While pain can be experienced in an area along this nerve pathway, it is most commonly felt from the lower back to the back of the thigh and calf.
The pain itself can be experienced in different ways and on different levels, depending on its underlying cause. Some people describe it as sharp and shooting; for some, it’s more of a burning or stabbing sensation. Others only experience mild tingling or a dull ache. The pain may be constant or experienced in intervals.
Sciatica pain usually only occurs on one side of the body and is often accompanied by a feeling of numbness in surrounding areas of the leg, hip, or lumbar region. It is also observed that sciatica pain gets worse after:
- Prolonged periods of sitting or standing
- Coughing and sneezing
- Laughing
- Bending backwards
- A forced or sudden body movement
Whilst it usually occurs on one side, it is possible to experience sciatica pain on both sides of the body. Depending on the cause, the pain may occur suddenly or develop gradually over time.
Causes of Sciatica
Sciatica is caused by injury, irritation, or inflammation of the sciatica nerve due to unexpected pressure exerted on the nerve. Several things may pinch the sciatic nerve, leading to sciatica:
- A herniated or slipped disc: The most common cause of sciatica is a slipped herniated disc putting pressure on the root of the sciatic nerve. A spinal disc can herniate due to pressure exerted from the vertebrae on top of it, and in turn, it can press on the sciatic nerve.
- Spinal stenosis: Abnormal narrowing of the spinal canal, known as spinal stenosis, results in the spinal cord pressing against the sciatic nerve, causing sciatica.
- Degenerative disc disease: Spinal discs wear down and shorten, resulting in spinal stenosis.
- Spondylolisthesis: In some cases, spinal vertebrae slip and narrow the opening for the nerve. As a result, the extended spinal bone presses on the sciatic nerve and causes inflammation.
- Osteoarthritis: Another common cause of sciatica is osteoarthritis or bone spurs that form in ageing spins and compress lower back nerves, including the sciatic nerve.
- Pelvic or spinal injury: Sciatica is sometimes a result of pelvic and spinal injury affecting the sciatic nerve.
- Tumors: Tumor growth in the lumbar region can press and pinch the sciatic nerve.
- Piriformis syndrome: Spasms in the piriformis muscle in the buttocks can put pressure on the sciatic nerve.
- Cauda equina syndrome: Another rare condition that can cause sciatica is cauda equina syndrome, with affects the bundle of nerves at the end of the spinal cord, including the sciatic nerve.
Risk factors of Sciatica
- Risk factors for sciatica include:
- Age: The risk of herniated discs and bone spurs increases with age.
- Obesity: Obesity increases the pressure on the spine, which may result in sciatica.
- Occupation: Jobs that require strenuous physical labour increase the risk of sciatica.
- Diabetes: High blood sugar due to diabetes causes nerve damage and may increase the chances of sciatica.
Diagnosis and treatment
People experiencing lower back pain should consult their doctor to determine whether they have sciatica. The first step to diagnosing sciatica is a physical exam in which the doctor may ask the patient to:
- Walk on their toes and heels
- Raise and straighten their leg
- Lie on the back with legs straightened out
- Stretch in different ways
The physical exam aims to pinpoint the affected nerves, check muscle flexibility and strength, and identify whether a disc is herniated. Depending on the results of the physical exam, the doctor may conduct other tests such as:
- Spinal X-rays to rule out spinal fractures
- MRIs to show pressure on the nerve and disc herniation
- CT scans to see detailed images of the bone
- Nerve conduction velocity tests to see how well electrical impulses travel through the sciatic nerve
- Myelogram to check whether a vertebra or spinal disc is causing the pain
The appropriate treatment follows a diagnosis of sciatica to decrease the pain and increase leg movement and functioning. Mild cases of sciatica can be treated at home by:
- Applying ice or hot packs to the affected area. This helps reduce the swelling and alleviate pain.
- Taking over-the-counter medicines to reduce pain, swelling, and inflammation. Non-steroidal anti-inflammatory drugs are the most common.
- Gentle exercise and stretches can help alleviate sciatica
More severe and persistent cases of sciatica can be treated through:
- Prescription medicines to relieve discomfort and reduce pain.
- Physical therapy to improve muscle flexibility.
- Spinal injections to reduce swelling and pain around the nerve root.
- Spinal surgery is reserved as a last resort treatment.
- Alternative treatments include acupuncture and chiropractic treatments.
Prevention of Sciatica
Lower back pain caused by sciatica can be prevented in some cases by:
- Exercising regularly to improve core muscle strength and achieve and maintain proper posture.
- Keeping proper posture while sitting to avoid pressure on the lower back.
- Maintain a healthy weight.
- Avoid smoking to prevent nicotine from weakening the spine and the vertebral discs.
- Avoid activities that hurt the back.
- Avoid prolonged sitting
