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Pre-eclampsia: the signs worth knowing
A serious condition that's very manageable when caught early.
Updated · Sources
Pre-eclampsia is one of the few pregnancy complications worth learning the warning signs for by heart. It affects a small number of pregnancies, usually after 20 weeks, and it's very treatable when caught early — but it can become serious if missed. Knowing what to watch for isn't about anxiety; it's about catching it in time.
What it is
Pre-eclampsia is a problem with the placenta that shows up as high blood pressure plus signs that other organs (often the kidneys) are under strain. That's why every antenatal visit checks your blood pressure and your urine — they're screening for it before you'd ever feel it.
Call your provider the same day if you notice
- A bad headache that doesn't ease with paracetamol.
- Vision changes — blurring, flashing lights or spots.
- Pain just below your ribs, usually on the right.
- Sudden swelling of the face, hands or feet.
- Feeling suddenly very unwell, or a lot of vomiting in late pregnancy.
Who's more at risk
Risk is higher with a first pregnancy, a previous history of pre-eclampsia, existing high blood pressure, diabetes or kidney disease, carrying twins, or being over 40. If you have risk factors, your provider may suggest a low-dose aspirin from early in the second trimester — this is well-evidenced and reduces the chance of developing it.
What happens if you have it
Mild cases are monitored closely with more frequent checks. More significant cases may need medication to control blood pressure and, ultimately, the only cure is the birth of the baby — so timing of delivery is balanced carefully. It can also appear in the days after birth, so keep watching for the signs postpartum.
Why routine checks matter
Pre-eclampsia often causes no symptoms at first. That is why your blood pressure is measured and your urine is checked for protein at antenatal appointments throughout pregnancy. Going to every appointment, even when you feel well, is one of the most effective ways to catch it early.
If a reading is raised, you may be asked to come back for repeat checks, have blood tests, or be monitored in a day assessment unit. A single high reading does not always mean pre-eclampsia, but it does mean your team will want to look more closely.
Symptoms that can be mistaken for normal pregnancy
- Swelling: some swelling of the feet and ankles is common in pregnancy, but sudden swelling of the face, hands or feet should be checked.
- Headaches: a headache that is severe or does not go away with simple painkillers is a warning sign.
- Heartburn-like pain: pain just below the ribs, especially on the right, can be mistaken for indigestion.
- Vision changes: blurring, flashing lights or spots in front of the eyes.
- Feeling generally very unwell, or vomiting in the second half of pregnancy.
Prevention if you are at higher risk
If you have risk factors — such as pre-eclampsia in a previous pregnancy, high blood pressure before pregnancy, kidney disease, diabetes or an autoimmune condition — your doctor or midwife may recommend a daily low-dose aspirin, usually starting in the first half of pregnancy and continued until the baby is born. Only take aspirin in pregnancy if a health professional has recommended it.
You may also be offered more frequent blood pressure checks and extra scans to follow your baby’s growth.
After the birth
Pre-eclampsia can develop or get worse in the days after birth, so keep watching for the same warning signs once you are home. Blood pressure checks usually continue after birth, and some people need blood pressure medicine for a while.
Having pre-eclampsia can make it more likely in a future pregnancy and is linked with a higher risk of high blood pressure later in life, so it is worth keeping up regular blood pressure checks with your doctor.
Common questions
When does pre-eclampsia usually start?
It usually develops after 20 weeks of pregnancy, most often later in pregnancy, and it can also appear in the days or weeks after birth.
Can pre-eclampsia be cured?
The condition resolves after the baby and placenta are delivered. Until then, it is managed with close monitoring and sometimes medicines, and your team plans the safest timing for birth.
Should I take aspirin to prevent pre-eclampsia?
Only if your doctor or midwife recommends it. Low-dose aspirin is advised for people at higher risk, at a dose and start date your team will give you.
Is swelling in pregnancy always a sign of pre-eclampsia?
No. Mild swelling of the feet and ankles is common. Sudden swelling of the face, hands or feet, especially with other symptoms, should be checked the same day.
Sources & editorial process
- ACOG — Preeclampsia and high blood pressure during pregnancy
- NHS — Pre-eclampsia
- NICE guideline NG201 — Antenatal care
Written by the Elara editorial team from the sources above. This page has not been reviewed by an independent clinician. Read how we write and update health pages. Last updated .
Medical disclaimer: this page is general education, not medical advice, diagnosis or treatment. If you are worried about yourself or your baby, contact your midwife, doctor or maternity unit straight away. In an emergency call your local emergency number.