Sciatica: back pain that radiates down the leg

Between the vertebrae there are intervertebral discs. If a disc is weakened, its contents can press on a nerve root. When this affects the sciatic nerve, the condition is called sciatica. The pain arises in the back, but it spreads down one of the legs [1].

The disc may be stretched or have a tear where core material has pushed out. Sciatica occurs in all age groups, but is most common between 30 and 50 years of age [1].

Typically it feels like pain from the lower back that runs down one leg. Many have had back pain and stiffness for some time before the symptoms get worse [1]. During the first days the pain is often intense, and it usually eases after a few days [1].

With sciatica the pain in the calf is often stronger than the back pain. Some feel tingling or numbness down the leg, and the pain can get worse with coughing and sneezing [2]. If the nerve is pressed harder, it can cause reduced sensation in the skin, weakness in the muscles or weakened reflexes [1].

The nerve root most often affected is called L5. The pain is then felt on the outside of the thigh, the front of the lower leg, over the top of the foot and towards the big toe [1].

The history and the examination often give a reasonably certain diagnosis [1]. During the examination the straightened leg is lifted. Pain in the affected area is regarded as a typical finding. A neurological examination of sensation, muscle strength and reflexes is also carried out [1].

Imaging is usually not necessary in classic sciatica at the start, because the symptoms often go away by themselves. It may be relevant for persistent pain, if another disease is suspected or when surgery is considered. MRI is preferred because it shows soft tissue best. Findings on images can be unrelated to the symptoms [1].

In the first phase one waits and follows the development. Staying in motion is recommended rather than bed rest, and short walks should be started early. You should avoid loads that make the pain worse. With very severe pain it may be necessary to lie still for a period [1].

Once the acute period of pain is over, exercise is regarded as helpful for getting going again. Strengthening the abdominal and back muscles appears to be useful, and physiotherapy should aim for the patient to be able to exercise independently [1]. NHI writes that research has not shown that chiropractic or general physical therapy improves sciatica [1].

Surgery is relevant if the pain does not improve within a few weeks or a few months. About 10 percent of those with sciatica are assumed to need surgery [1].

NHI states that 80 to 90 percent gradually improve within days and are well within four months [1]. Most have had back problems before, and many get symptoms again after the period of sciatica is over [1].

Most who were working return to their previous work. Early contact with the workplace is recommended, and long-term sick leave can reduce the chance of returning [1].

If you lose control of urination or bowel movements, it can be a sign of cauda equina syndrome. It is rare, but requires urgent help [1].

A prompt medical assessment is relevant with rapidly increasing paralysis, or with persistent severe pain that requires strong painkillers [1]. One-sided radiating pain below the knee is also a sign that you should contact a doctor, as is marked muscle weakness or loss of sensation [2].

If the symptoms do not improve within a few weeks or a few months, they should be assessed again [1].

A chiropractor can take a history, examine the back and the nerve function in the leg, and assess whether there are signs that should be followed up by a doctor. You can also get guidance on activity and exercise. You can read more about chiropractic at Dr.Dropin, and the page on disc herniation describes the condition that often lies behind sciatica.

What is sciatica?

Sciatica is pain from the lower back that spreads down one leg. It is most often caused by an intervertebral disc pressing on a nerve root [1].

How long does sciatica last?

NHI states that 80 to 90 percent gradually improve within days and are well within four months. Many still get back problems again later [1].

Should I rest when I have sciatica?

Bed rest over time is not recommended. You should stay in motion and start with short walks early, and avoid loads that make the pain worse [1].

Do I need an MRI for sciatica?

In classic sciatica at the start, imaging is usually not necessary. MRI is relevant for persistent pain, when another disease is suspected or when surgery is considered [1].

When does sciatica need surgery?

Surgery is relevant if the pain does not improve within a few weeks or a few months. With rapidly increasing paralysis or cauda equina syndrome, a prompt assessment is needed [1].

The page about lower back pain describes back pain that does not radiate into the leg. You can find more articles in the overview of articles.

This article was written by Dr.Dropin Fysikalske and is based on the sources listed below. It gives general information and does not replace an examination by a healthcare professional.

The websites were accessed and read on 22 October 2026.

1. Isjias og prolaps i korsryggen (Sciatica and disc herniation in the lower back). NHI.no. Last updated 15 January 2026. Link

2. Korsryggsmerter: symptomer og alarmsignaler (Lower back pain: symptoms and warning signs, symptom guide). NHI.no. Last updated 5 October 2020. Link