The sciatic nerve is the largest single nerve in the human body. Formed of five nerve roots in the lumbar and sacral spine, the sciatic nerve starts in the lower back and runs down the back of each leg. The body has two sciatic nerves, one on each side – the right and left legs. The nerve controls the muscles on the back of the knee and lower leg. It also provides sensation to the back of the thigh, the outer and back part of the lower leg, and the sole, according to a report on the US-based Cleveland Clinic’s website.

What are the symptoms of sciatica?

The symptoms of sciatica vary widely. Generally, it may feel like a dull ache or burning sensation in the back, running down the buttock to the back of the thigh and the calf. It can also feel like an electric shock. Some people experience mild tingling, weakness or numbness in the leg or hip.

How is sciatica diagnosed?

Healthcare providers use a combination of methods to diagnose sciatica. Generally, the symptoms give a fair idea. A report in Penn Medicine of the University of Pennsylvania says, besides flexibility and strength checks, they will also conduct a physical examination to find out the following:

• Visible changes in walking

• Weakness when bending the knee

• Difficulty bending the foot inwards or down

• Difficulty walking on toes

• Difficulty bending forward or backward

• Abnormal or weak reflexes

• Loss of sensation or numbness

• Pain when lifting the leg straight up while lying on the back

How common is sciatica?

Sciatica is a very common condition. About 40 per cent of people experience some form of sciatica, according to the Harvard Medical School. Although it rarely happens before age 20, it becomes more frequent as people age. Men between 30 and 50 are more likely to have sciatica.

What causes sciatica?

Sciatica occurs when there is pressure on the sciatic nerve. It could also result in an injury. The common causes are:

• Slipped or herniated disc: When the soft tissue between the bones (vertebrae) in your spine seeps out

• Spinal stenosis: Narrowing of the part of your spine where nerves pass through

• Spondylolisthesis: When one of the vertebrae (bones in your spine) slips out of position

• Back or pelvic injury

• Piriformis syndrome: A pain disorder involving the narrow muscle in the buttocks

• Tumours, cysts or other growths

• Osteoarthritis

• Pregnancy

How is sciatica treated?

No treatment is required in mild cases, and recovery occurs over time. Bed rest is NOT recommended. Start mild exercises after the pain dissipates. But continued pain will require treatment, depending on the severity of the condition.

Self-treatment

In cases of mild pain, self-treatment can be helpful. If the pain doesn’t go away, seek professional help. These are some self-help tips from the Harvard Medical School:

1. Reduce physical activity for the first few days before resuming them slowly.

2. Avoid lifting heavy objects, and do not twist the back.

3. Ice or heat packs: They can help reduce pain and swelling during the first few days of pain. Apply ice packs (wrapped in a towel) for 20 minutes at a time, several times a day. After the first several days, switch to a heating pad or warm compress. Apply heat for 20 minutes at a time.

4. Physical activity: This is best learnt from a physiotherapist or a sports medicine expert. It will strengthen core muscles.

5. Seek professional help: If the self-care doesn’t help after a few weeks, it’s time to consult a doctor.

Regular treatments

Prescription medications: Painkillers, muscle relaxants and other medications may help relieve sciatica symptoms.

Physiotherapy: A physiotherapist will ask the patient to do exercises to reduce pressure on the sciatic nerve. Stretching exercises, walking, swimming and water aerobics will also help.

Spinal injections: Injections like corticosteroids may provide short-term relief (typically up to three months). But this is no substitute for therapies that give long-term relief.

Alternative therapies: A chiropractor to adjust the spine, yoga, acupuncture and massage therapy might also help.

Surgery

Surgery to relieve the compression of spinal nerves is an option when sciatica is very severe. It is usually a last resort when all other treatments fail. Doctors recommend surgery only if the pain that prevents a person from carrying out their normal routine. Particularly if the patient has symptoms of nerve damage or a possibility of nerve injury. A Mayo Clinic report said people with severe leg weakness or bowel or bladder changes might need surgery.