Why is my back pain shooting down my leg?

Back pain is often expected to stay in the lower back, so it can feel unsettling when the pain starts travelling into the buttock, thigh, calf or foot.

For some people, it feels sharp, burning or electric. For others, it shows up as tingling, numbness, heaviness or weakness in the leg. Sometimes, the leg pain can feel worse than the back pain itself, which can make the symptoms feel confusing.

This usually happens because the nerves in the lower spine are involved. Understanding how those nerves work can help explain why pain travels down the leg, and when it is important to get symptoms checked.

What is sciatica, and why does it happen?

Sciatica is different from general back pain. It describes pain, tingling, numbness or weakness that starts in the lower back or buttock and travels down one leg.

This happens when a nerve in the lower back becomes irritated or compressed. The pain can then follow the pathway of the sciatic nerve, which runs from the lower spine, through the buttock and down the leg.

The sciatic nerve helps control sensation and muscle function in parts of the leg and foot. This is why irritation in the lower spine can cause symptoms much further down the leg.

Common causes include a slipped or bulging disc pressing on a nerve root, inflammation around the nerve, age-related changes in the spine, or narrowing around the spinal nerves, known as spinal stenosis.

How does a problem in the back cause pain in the leg?

Between the bones of the spine are discs that act like cushions. If part of a disc bulges or protrudes, it can press on a nearby nerve. Inflammation can also develop around the nerve root, making the nerve more sensitive.

The pain travels because the irritated nerve carries signals along its usual pathway. Your brain may then interpret the problem as pain extending down the leg, even though the source is often in the lower back.

This can also cause tingling, pins and needles, numbness, muscle weakness or a heavy feeling in the leg or foot.

What does sciatica usually feel like?

Sciatica can vary, but it often follows a recognisable pattern. The pain usually travels from the lower back or buttock into one leg. It may feel sharp, burning or shooting, and it can be associated with tingling or numbness.

Some people find the pain becomes worse when they cough, sneeze, bend forward or sit for a long time. It often affects one side of the body and may travel below the knee. In some cases, the leg pain is more noticeable than the back pain.

Many episodes gradually improve over several weeks, especially when the nerve irritation settles.

When should symptoms be treated as urgent?

Most sciatica is not dangerous, but some symptoms can suggest more serious nerve compression and should not be ignored.

Seek urgent medical help, such as A&E or 999, if you develop loss of bladder or bowel control, numbness around the groin or inner thighs, significant leg weakness, difficulty walking, or difficulty lifting the front of the foot.

Numbness around the groin or inner thighs is often called saddle numbness. Together with bladder or bowel changes, it can be a warning sign of a rare but serious condition affecting the nerves at the base of the spine.

You should also seek prompt medical advice if back or leg pain happens with fever, feeling generally unwell, unexplained weight loss, severe pain at night or pain after a significant injury.

What can help sciatica symptoms settle?

Many cases of sciatica improve without surgery, although recovery time varies depending on how irritated the nerve is.

Gentle movement is usually more helpful than staying in bed for long periods. Short walks, light stretching and slowly returning to normal activities can help keep the back moving without overloading it.

Pain relief can also make movement easier. Some people find heat or cold packs helpful for 15 to 20 minutes at a time. Over-the-counter pain relief, such as paracetamol or ibuprofen, may also help if it is suitable for you.

Try to avoid sitting still for long periods, as this can make symptoms feel worse. A physiotherapist can guide exercises that support recovery and help you move more confidently.

At night, some people feel more comfortable sleeping with a firm pillow under the knees when lying on their back, or a small pillow between the knees when lying on their side.

When should I seek medical advice?

It is worth speaking to a GP, physiotherapist or specialist if the pain lasts beyond several weeks, symptoms are getting worse rather than improving, numbness or weakness develops, or daily activities are becoming difficult.

A clinician may check your muscle strength, reflexes, sensation and nerve function. They can also advise whether imaging, such as an MRI scan, is needed.

Depending on the cause and severity of symptoms, treatment may involve physiotherapy, medication, injections or further specialist care.

What this means for your back and nerve health

Back pain that shoots down the leg is commonly caused by irritation of a spinal nerve, often referred to as sciatica.

Although it can be painful and disruptive, many cases improve gradually with time, movement and conservative treatment. The most important thing is noticing whether symptoms are settling, worsening or changing.

Weakness, numbness, difficulty walking, foot drop, or bladder and bowel changes need urgent attention. Getting the right level of care at the right time can help protect nerve function and support recovery.

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Medically Reviewed
Last reviewed on 02/06/2026