What sciatica actually is

The NHS: "Sciatica happens when the sciatic nerve, which runs from your lower back to your feet, is irritated or compressed." The symptoms "usually affect your bottom and the back of one leg, often including your foot and toes", and you may feel "a sharp, burning pain down the back of the leg", "tingling — like pins and needles", numbness and weakness.

Then comes the sentence that resolves most of the confusion: "You probably do not have sciatica if you only have back pain." The NHS also notes that you may have back pain as well, "but it's not usually as bad as the pain in your leg".

So the test is simple. Does the pain travel down a leg? If not, it is back pain, and back pain in pregnancy is a different and more common problem with different advice attached to it.

The NHS adds that symptoms "may come on suddenly but they can also start slowly", and that "the pain may be worse when moving, sneezing or coughing".

Why pregnancy provokes it

The NHS explains the general pregnancy back situation: "During pregnancy, the ligaments in your body naturally become softer and stretch to prepare you for labour. This can put a strain on the joints of your lower back and pelvis."

Add a shifted centre of gravity, extra load through the lumbar spine, and swelling in tissues around the nerve, and you have the conditions for irritation. ACOG makes the same connection for back pain generally, describing how the growing uterus and hormonal changes alter the load on the spine.

What is worth knowing: the NHS expects sciatica in the general population to get "better in a few weeks to a few months", though it can last longer, and it can return. Pregnancy does not change the fundamental nature of the condition, but it does remove some of the treatment options.

Sciatica, pelvic girdle pain and back pain

These three get muddled constantly, and they are managed differently.

Sciatica travels down one leg, often past the knee to the foot and toes, with tingling or numbness. Worse with movement, sneezing and coughing.
Pelvic girdle pain sits over the pubic bone, in the lower back, in the perineum or spreading to the thighs, often with clicking or grinding. Provoked by walking, stairs, standing on one leg, turning over in bed and parting your legs.
Back pain stays in the back. It is very common, and the NHS lists straightforward measures for it.

The distinction matters because NICE's antenatal care guideline attaches a physiotherapy referral to pelvic girdle pain specifically — "consider referral to physiotherapy services for exercise advice and/or a non-rigid lumbopelvic belt" — and describing your leg pain as "hip pain" can send you down the wrong pathway.

What the NHS says helps

Its advice for sciatica is unusually direct about what to do and what not to do:

Carry on with your normal activities as much as possible.
Start gentle exercise as soon as you can — "anything that gets you moving can help".
Hold heat packs to the painful areas, available from pharmacies.
Do not sit or lie down for long periods — "even if moving hurts, it's not harmful and can help you get better faster".

That last instruction is the one people find hardest to believe and the one most worth following. Rest is not the treatment.

The HSE's pregnancy back pain advice adds the everyday mechanics that reduce load on the lower spine: bend your knees and keep your back straight when lifting, avoid lifting heavy objects, move your feet rather than twisting your spine, wear flat shoes, balance shopping between two bags, and support your back when sitting.

Painkillers, honestly

The NHS's general sciatica page is candid: "paracetamol is unlikely to help and it's not clear how much NSAIDs, such as ibuprofen, help with sciatica". Its pregnancy back pain advice, meanwhile, is that "you can take paracetamol to ease back pain while you are pregnant, unless your GP or midwife says not to".

Put those together and the position is: paracetamol is the option that is safe in pregnancy and may not do much for nerve pain specifically. Anti-inflammatories are a separate conversation to have with your midwife, GP or pharmacist rather than something to start from a packet. Do not take anything new without asking.

Getting referred

The NHS notes that "in many areas you may be able to get help, such as physiotherapy, from NHS community musculoskeletal (MSK) services without needing a referral from a GP". Its pregnancy back pain page adds that if backache is very painful, your GP or midwife "may be able to refer you to an obstetric physiotherapist at your hospital". An obstetric physiotherapist is the right person here — they see this constantly and will adapt exercises to a bump.

See a GP, the NHS says, if the pain has not improved after a few weeks of home treatment, is getting worse, or is stopping you doing your normal activities.

The emergency list

The NHS says to go to A&E or call 999 if you:

Have sciatica on both sides.
Have weakness or numbness in both legs that is severe or getting worse.
Have numbness around or under your genitals, or around your bottom.
Find it hard to start peeing, cannot pee, or cannot control when you pee — and this is not normal for you.
Do not notice when you need to poo, or cannot control when you poo.

The NHS's pregnancy back pain page carries the same instruction in shorter form: call 999 or go to A&E if you have back pain and "you lose feeling in one or both of your legs, your bum, or your genitals". These are signs of compression of the nerves at the base of the spine, and how quickly it is treated affects the outcome.

When to call someone

Your local emergency number — 999 in the UK and Ireland, 911 in the US and Canada, 000 in Australia, 111 in New Zealand — for any of the symptoms in the emergency list above.
Your GP or midwife urgently if back or leg pain comes with fever, vaginal bleeding, pain when you pee, or pain in your sides under the ribs (NHS).
Your midwife or maternity unit if the pain is rhythmic, comes and goes in waves, or arrives with tightenings — the NHS lists back pain in the second or third trimester as a possible sign of early labour.
Your GP or midwife if pain is not improving after a few weeks, is getting worse, or is stopping you doing normal things — and ask specifically about physiotherapy.

The short version

If it travels down one leg with tingling or numbness, it is sciatica; if it stays in your back, it is not. Keep moving, use heat, accept that resting makes it worse, and get referred to an obstetric physiotherapist rather than waiting it out. Numbness in both legs or anywhere near the saddle area, or new problems peeing, is an emergency tonight.

Sciatica in Pregnancy