The earliest and most defining sign of preeclampsia is high blood pressure, specifically readings at or above 140/90 mm Hg, developing after 20 weeks of pregnancy. But blood pressure is something your provider measures at appointments, not something you necessarily feel. That’s what makes preeclampsia tricky: many of its warning signs are subtle or easy to mistake for normal pregnancy discomforts, and some women have no obvious symptoms at all before a routine check reveals a problem.
The Core Signs
Preeclampsia was once defined by a triad of high blood pressure, protein in the urine, and swelling. The modern understanding is broader. It’s now diagnosed based on high blood pressure plus evidence of organ stress, which can show up in the kidneys, liver, blood, brain, or placenta. Protein in the urine is still a common finding, but it’s no longer required for a diagnosis if other signs of organ involvement are present.
The signs you might notice yourself include:
- Swelling in your face, hands, and ankles that seems sudden or excessive compared to the gradual puffiness many pregnant people experience in their feet and legs
- Rapid weight gain over a few days, caused by your body retaining water
- Headaches that are persistent or unusually severe
- Vision changes such as blurry vision, sensitivity to light, or dark spots that don’t go away
- Pain in your upper belly, typically under the ribs on the right side
- Nausea or vomiting that starts in the second half of pregnancy, distinct from first-trimester morning sickness
- Decreased urination despite drinking normal amounts of fluid
- Shortness of breath
Some of these, like swollen ankles and headaches, are extremely common in normal pregnancies. The difference is usually in the severity and timing. A headache that won’t respond to rest or typical pain relief, swelling that appears suddenly in your face and hands rather than gradually in your legs, or vision changes of any kind are all reasons to call your provider right away rather than wait for your next appointment.
Signs of Severe Preeclampsia
Preeclampsia exists on a spectrum, and the severe end carries significant risks for both you and the baby. Severe features include a persistent, intense headache that doesn’t improve with medication, visual disturbances like seeing spots or flashing lights or temporary loss of vision, and altered mental status such as confusion or difficulty concentrating. These symptoms reflect the condition’s effect on the brain and nervous system.
Upper abdominal pain, especially on the right side or behind the breastbone, is another red flag. This pain signals liver involvement and won’t respond to antacids or repositioning the way heartburn would. Your provider may check blood work showing elevated liver enzymes or a drop in platelet count, both markers that the condition is progressing.
New shortness of breath or difficulty breathing while lying flat can indicate fluid buildup around the lungs. Any of these symptoms appearing together, or worsening over hours rather than days, signals that the condition is moving into dangerous territory.
HELLP Syndrome
HELLP syndrome is a severe complication classified as a subset of preeclampsia. It involves the breakdown of red blood cells, elevated liver enzymes, and a dangerously low platelet count. It occurs in roughly 10% to 20% of pregnancies already complicated by severe preeclampsia.
What makes HELLP particularly concerning is that up to 15% of cases develop without high blood pressure or protein in the urine, meaning the classic preeclampsia warning signs may be absent. The symptoms you’d feel are often the same as severe preeclampsia: right-sided upper belly pain, nausea, vomiting, headache, and a general sense that something is very wrong. Up to 30% of HELLP cases appear after delivery rather than before, typically within the first 48 hours postpartum. When treated, it usually begins improving within 24 to 48 hours.
Signs That Show Up After Delivery
Preeclampsia doesn’t always end when the baby is born. Most cases of postpartum preeclampsia develop within 48 hours of childbirth, but late-onset cases can appear up to six weeks later. This catches many new parents off guard, especially if they had a healthy pregnancy with no blood pressure concerns.
The symptoms mirror those during pregnancy: blood pressure at or above 140/90, severe headaches, vision changes, upper belly pain, nausea, shortness of breath, and decreased urination. Because the postpartum period is already filled with exhaustion, headaches, and general discomfort, these signs are easy to dismiss. A severe headache in the first few weeks after delivery, particularly one that doesn’t improve with rest and hydration, is worth a blood pressure check and a call to your provider.
What Your Baby’s Monitoring May Reveal
Preeclampsia restricts blood flow through the placenta, which can affect your baby before you notice symptoms yourself. At prenatal appointments, your provider may pick up signs like slower-than-expected fetal growth or reduced amniotic fluid levels on ultrasound. These findings don’t always mean preeclampsia is the cause, but they often prompt closer monitoring, including blood pressure checks and lab work to look for the condition.
If you’re told your baby is measuring small for gestational age or that your fluid levels are low, ask whether preeclampsia is being considered. These fetal signs sometimes appear before the more recognizable maternal symptoms do.
Monitoring Blood Pressure at Home
If your provider has asked you to track blood pressure at home, or if you’re at higher risk and want to keep an eye on it, an arm-cuff monitor (not a wrist model) is the most reliable option. Have your provider check the device and watch you use it at least once to confirm you’re getting accurate readings.
To get a reliable measurement, avoid eating, drinking, or exercising for 30 minutes beforehand. Sit in a chair with back support, feet flat on the floor, legs uncrossed. Rest your arm on a table at about heart level, using a pillow to prop it up if needed. Place the cuff on bare skin, not over clothing. Don’t talk during the reading. Take two readings one to three minutes apart and record both. Try to measure at the same time each day.
Any reading at or above 140/90 during pregnancy warrants contacting your provider, even if you feel fine. Preeclampsia can progress from mild to severe quickly, and catching a blood pressure rise early gives your care team more options.
Reducing Your Risk
For people at high risk, the U.S. Preventive Services Task Force recommends a daily low-dose aspirin (81 mg) starting after 12 weeks of pregnancy. High-risk factors include a history of preeclampsia in a previous pregnancy, carrying multiples, chronic high blood pressure, diabetes, kidney disease, or autoimmune conditions. Studies show this simple step meaningfully reduces the chance of developing preeclampsia, though it doesn’t eliminate the risk entirely. If you have any of these risk factors, bring up aspirin prophylaxis early in your prenatal care so it can be started in the right window.