The short explanation
Swelling of the feet and ankles by evening is very common in the last months of pregnancy. The growing womb slows blood returning from the legs and the body holds more fluid, especially in hot weather or after standing or sitting for long. It usually improves overnight or when you raise your feet. But swelling can sometimes be part of pre-eclampsia, a condition of high blood pressure in pregnancy. The warning signs are swelling that comes on suddenly, swelling of the face, hands or around the eyes, and swelling with headache, vision changes or pain under the ribs. A BP check and a urine test are a simple way to tell, so it is worth getting them done.
What depends on your situation
The parts of this that change from woman to woman. Uncertainty is stated, not hidden.
- First pregnancy, age over about forty, a previous pre-eclampsia, twins, diabetes, kidney problems and high BP before pregnancy all raise the risk.
- Many PHCs and sub-centres can check BP and urine for protein without cost, if your next antenatal visit is far away.
- Raising your feet, avoiding standing for long, walking gently and lying on your left side can ease ordinary swelling.
- Swelling in one leg only, with pain or redness, is different and needs checking the same day.
What this answer cannot determine
The boundary of online education. These need a clinician who can see you.
- This cannot tell you whether your BP is normal. Only a BP reading and urine test can show that.
Questions for your clinician
Take these with you. You can add any of them to an appointment card.
- Is my blood pressure normal today?
- Is there protein in my urine?
- Am I at higher risk of pre-eclampsia?
- Which symptoms should make me come in straight away?
When to seek help
Clinician-approved guidance for this topic. When in doubt, being seen is never the wrong choice.
Emergency — call 112 now
- Call 112 or go to the nearest emergency department if you have a severe headache that does not settle, blurred vision or flashing lights, pain below the ribs, sudden swelling of the face or hands, fits, or breathlessness.
Get help the same day
- Get care the same day if the swelling came on suddenly, or if one leg is swollen and painful.
Book an appointment soon
- See your clinician within a few days for a BP and urine check if the swelling is increasing.
Raise it at a routine appointment
- Keep your routine antenatal visits, where BP and urine are checked every time.
Sources
The evidence this explanation is built on.
- Pre-eclampsia NHS
- Prenatal care MedlinePlus (NIH)
- Pregnancy MedlinePlus (NIH)
Who wrote and reviewed this
Every AskHer answer names its author. A clinically reviewed answer also names the clinician who signed it off — if no clinician is named below, it has not been clinically reviewed.
- Author
- AskHer Editorial (AI-assisted draft) AskHer's editorial team — not an individual clinician Works in English, தமிழ், हिन्दी
- Clinical reviewer
- Nobody yet No clinician has signed this answer off, and no person on the editorial team has read it yet. That is what the “Written with AI assistance” label means. It is queued for an editor to read, and then for a clinician who works in this area. The sources it was drafted against are listed above.
- Review status
- Written with AI assistance — not yet reviewed by a person
- Last reviewed
- Not yet reviewed by a person
- Version
- 1
Correction history
Substantive changes are listed, not quietly edited away.
No corrections have been made since this answer was first published.
Did this answer your question?
Whatever you choose is filed against this version of the answer, never against you, and it is never shown as a count.
“Explain more simply” asks you which part was hard to follow, so the author knows what to rewrite. “My question is different” opens a private follow-up with this answer attached.
Saving, following up and reporting are all private. Nothing you do on this page is visible to other readers or to the doctor who wrote it, unless you ask a question.