Signs of Preeclampsia Every Pregnant Person Should Know
Preeclampsia is a pregnancy complication marked by new high blood pressure, usually after 20 weeks, often together with signs of organ stress such as protein in the urine, headaches, vision changes, or upper abdominal
Written By: DocAi Health Editorial Team
Last Updated: 2026-07-22
Medically Reviewed By: DocAi Health Medical Review Team
Preeclampsia is a pregnancy complication marked by new high blood pressure, usually after 20 weeks, often together with signs of organ stress such as protein in the urine, headaches, vision changes, or upper abdominal pain. It affects roughly 1 in 25 pregnancies in the United States and can progress quickly, so recognizing the warning signs and getting regular prenatal blood pressure checks matters. Left untreated, severe preeclampsia can become life-threatening for both parent and baby, but with monitoring and timely care, most people who develop it go on to have safe deliveries.
What Preeclampsia Is
Preeclampsia happens when blood vessels, including those supplying the placenta, don't function normally, raising blood pressure and putting strain on organs like the kidneys, liver, and brain. The exact cause isn't fully understood, but it's believed to start early in pregnancy with abnormal development of the placenta's blood supply. It's diagnosed using a combination of blood pressure readings and lab findings, which is why routine prenatal visits, even when you feel fine, are an important safety net.
The Core Warning Signs
High blood pressure: A reading of 140/90 mmHg or higher, confirmed on two occasions, is the hallmark finding. This is why blood pressure is checked at every prenatal visit.
Protein in the urine: Detected through a urine test at prenatal visits; it's a sign the kidneys are under strain.
Severe or persistent headache: Different from a typical tension headache, often described as throbbing and not relieved by usual measures like rest or acetaminophen.
Vision changes: Blurred vision, seeing spots or flashing lights, temporary vision loss, or sensitivity to light.
Upper abdominal pain: Typically under the ribs on the right side, sometimes mistaken for heartburn or gallbladder pain.
Sudden swelling: Especially rapid swelling of the face and hands (some swelling of the feet is normal in pregnancy, but sudden, marked swelling elsewhere is not).
Rapid weight gain: More than 2 to 3 pounds in a week can reflect fluid retention from the condition.
Shortness of breath: Can indicate fluid buildup in the lungs in more severe cases.
Why It Can Be Easy to Miss
Many early preeclampsia symptoms, fatigue, mild swelling, occasional headaches, overlap with normal pregnancy discomforts, which is part of why routine screening matters so much. Some people have no symptoms at all until a routine blood pressure check flags the problem. This is exactly why prenatal appointments shouldn't be skipped, even when you feel well.
Risk Factors
Preeclampsia can occur in any pregnancy, but risk is higher with a first pregnancy, a personal or family history of preeclampsia, chronic hypertension, pre-existing diabetes, obesity, carrying multiples, maternal age over 35, kidney disease, and certain autoimmune conditions such as lupus. For people with significant risk factors, ACOG recommends discussing low-dose aspirin starting between 12 and 28 weeks of pregnancy as a preventive option.
How It's Managed
Management depends on severity and how far along the pregnancy is. Options range from closer monitoring (more frequent visits, blood pressure checks at home, lab work, fetal monitoring) to blood pressure medication, corticosteroids to support the baby's lung development if early delivery may be needed, and magnesium sulfate to prevent seizures in severe cases. Delivery of the baby and placenta is the only cure, and providers weigh the risks of continuing the pregnancy against the risks of early delivery on a case-by-case basis.
When to Seek Medical Care
Emergency, Call 911 or Go to the Emergency Room Immediately
- A severe, unrelenting headache that does not improve with rest or medication
- Vision changes: blurred vision, seeing spots or flashing lights, or temporary loss of vision
- Severe upper abdominal pain, especially under the ribs on the right side
- Shortness of breath or chest pain
- A seizure, or a blood pressure reading of 160/110 mmHg or higher
- Sudden, severe swelling of the face or hands together with any of the above
See a Doctor Soon (Same Day / Next Available Appointment)
- A home blood pressure reading of 140/90 mmHg or higher, confirmed on a repeat check
- New or worsening swelling of the face, hands, or legs
- Rapid weight gain of more than 2 to 3 pounds in a week
- A headache that is different or more persistent than your usual headaches
- Nausea or vomiting that is new in the second half of pregnancy
If you are ever unsure whether a symptom is an emergency, call your provider's after-hours line or go to labor and delivery triage. It's always reasonable to be evaluated.
Practical Takeaways
- Keep every prenatal appointment; blood pressure and urine checks catch preeclampsia before symptoms appear.
- Learn the warning signs above so you recognize them quickly if they occur.
- If your provider recommends home blood pressure monitoring, take it seriously and report elevated readings promptly.
- Symptoms can appear for the first time after delivery, stay alert for several weeks postpartum.
Frequently Asked Questions
At what week of pregnancy does preeclampsia usually start?
Preeclampsia is most often diagnosed after 20 weeks of pregnancy, and most commonly in the third trimester, though it can occasionally develop earlier or even show up shortly after delivery (postpartum preeclampsia). Regular prenatal visits, which include blood pressure checks and urine screening, are how it is often caught early.
Can preeclampsia happen without high blood pressure?
High blood pressure is a defining feature of preeclampsia, but some people notice other symptoms, such as a severe headache, vision changes, or upper abdominal pain, before or alongside a blood pressure reading. Any of these symptoms warrant prompt evaluation regardless of how you feel otherwise.
Who is at higher risk for preeclampsia?
Risk factors include a first pregnancy, a personal or family history of preeclampsia, chronic high blood pressure, pre-existing diabetes, obesity, carrying multiples (twins or more), being over age 35, and certain autoimmune conditions. ACOG recommends low-dose aspirin starting between 12 and 28 weeks of pregnancy for people with specific risk factors, this is a decision to make with your provider.
Does preeclampsia go away after delivery?
Delivery of the baby and placenta is the only definitive treatment for preeclampsia, and blood pressure typically improves over days to weeks postpartum. However, preeclampsia can also develop for the first time after delivery (postpartum preeclampsia), most often within the first week but sometimes up to six weeks after birth, so new headaches, vision changes, or swelling after delivery should still be reported to a provider.
Sources
- American College of Obstetricians and Gynecologists (ACOG): Preeclampsia and High Blood Pressure During Pregnancy FAQ.
- CDC: High Blood Pressure During Pregnancy.
- National Institute of Child Health and Human Development (NICHD, NIH): Preeclampsia and Eclampsia.
- MedlinePlus (National Library of Medicine, NIH): Preeclampsia.
- Mayo Clinic: Preeclampsia, symptoms and causes.