Sciatica: symptoms, causes and what helps

What sciatica is

The sciatic nerve is the largest nerve in the body. It is formed from nerve roots that leave the lower spine, runs through the buttock and down the back of the leg, then branches to supply the calf and foot. Sciatica is the name for pain, and sometimes pins and needles or numbness, that follows the path of that nerve because one of its roots is irritated or compressed.

Clinicians often call it lumbar radicular pain. The word sciatica describes the symptoms rather than the cause, which is why the first step is working out what is irritating the nerve and how sensitive it currently is.

Common causes and who gets it

The most common cause in adults under about 50 is a disc bulge or herniation pressing on or inflaming a nerve root. You can read more about that in our guide to disc bulges and herniated discs. Chemical irritation from the disc can matter as much as the physical pressure, which is partly why symptoms do not always match what a scan shows.

In older adults, narrowing of the spaces the nerves pass through (spinal stenosis) becomes more common. This tends to cause leg symptoms that build with walking or standing and ease when you sit or lean forward, such as leaning on a shopping trolley. Less often, a vertebra slipping slightly forward on the one below can be involved.

Risk rises with heavy manual work, long periods of sitting, smoking, and a history of back pain. It is common in people in their 30s and 40s, including people who train regularly.

Typical symptoms

• Pain in the buttock and down the back or side of one leg, often below the knee
• Leg pain that feels worse than the back pain
• Burning, shooting or electric pain, or a deep ache in the calf
• Pins and needles or numbness in part of the leg or foot
• Pain that flares with sitting, bending, coughing or sneezing
• Some weakness, such as difficulty standing on your toes or lifting your foot

A tight feeling in the back of the thigh after a heavy deadlift session is usually a muscle issue, not sciatica. The nerve pattern, the sensation changes and pain spreading below the knee are what point towards a nerve root.

What a physio assessment looks at

The assessment starts with screening questions about bladder, bowel and sexual function, numbness around the saddle area and your general health, because these rule out the rare emergencies. Then the physio looks at how the back and leg behave and how the nerve is working.

• Reflexes, sensation and muscle strength in both legs
• Nerve sensitivity tests such as the straight leg raise and slump test
• Which positions ease the leg pain and which flare it
• Your sleep, work demands and training, so the plan fits your week

Most people do not need an MRI straight away. Scans are usually reserved for people with severe or worsening neurological signs, or symptoms that are not settling and where an injection or surgery is being considered.

What usually helps

The general principle is to stay as active as the nerve allows. Short, frequent walks, positions that ease the leg pain and gradual exercise tend to work better than bed rest. A physio can help you find which movements calm your symptoms, which varies a lot from person to person, then build a graded programme for the back, hips and legs.

Manual therapy can ease pain for some people in the short term and may make it easier to exercise. Medication is a conversation for your GP or pharmacist, because some drugs commonly used for nerve pain have limited evidence for sciatica. For persistent, severe symptoms, a GP may refer you to a specialist to discuss options such as a spinal injection or, in a minority of cases, surgery.

What you can start with at home

1. Find your easing position. For many people it is lying on the back with the lower legs resting on a chair, or lying on one side with a pillow between the knees.
2. Walk little and often, stopping before the leg pain climbs sharply.
3. Break up sitting every 20 to 30 minutes, because sitting often aggravates disc-related sciatica.
4. Try gentle movements that stay comfortable, such as pelvic tilts or knee rocks, and stop anything that sends pain further down the leg.
5. Protect your sleep; a supported position and a regular routine help pain tolerance.

Avoid aggressive hamstring stretching in the early stage, since stretching an irritated nerve often flares it. Our guide on whether to rest or move with an injury explains how to judge a sensible amount of activity.

How long recovery takes and when to get help

Many people notice a clear improvement over 6 to 12 weeks, and a large proportion recover without surgery. Some take several months, and numbness can be the last thing to fade. If you are not improving after a few weeks, or you are struggling to work or sleep, get assessed. The on-site physio at Lycan Strength can see you, with 20% off for members, and you can book an appointment online.

• Call 999 or go to A&E if you have sciatica in both legs, numbness around the genitals or buttocks, new problems with bladder or bowel control, or new sexual dysfunction.
• Call NHS 111 or see your GP urgently if weakness in your leg or foot is getting worse, such as your foot slapping or catching when you walk.
• See your GP if leg pain comes with fever, unexplained weight loss, a history of cancer, or pain that is severe and constant at night.

Once you are moving freely, a return to lifting should be gradual. Our lower back pain guide covers how to rebuild load sensibly.

Questions