Understanding Preeclampsia and Eclampsia — the Basics

Written by Stephanie Watson
Medically Reviewed by Zilpah Sheikh, MD on April 01, 2025
7 min read

Preeclampsia and eclampsia are serious blood pressure issues that can happen during the second half of your pregnancy.

If you have preeclampsia, your blood pressure can go very high, above 140/90. This can put a severe strain on organs such as your heart, lungs, and kidneys. It can also keep your baby from getting enough oxygen and nutrients from your placenta.

Eclampsia includes symptoms of preeclampsia, along with seizures and coma (when you lose consciousness). This can be life-threatening for both you and your baby.

Both preeclampsia and eclampsia can start after 20 weeks of pregnancy and up to six weeks after your baby is born.

Who gets preeclampsia and eclampsia?

Preeclampsia affects between 5% and 8% of all pregnancies in the U.S. Eclampsia is less common and affects less than 3% of all those with preeclampsia.

Your risk of preeclampsia is higher if:

  • This is your first pregnancy.
  • You have a family history of preeclampsia.
  • You’re carrying multiples (twins or more).
  • You’re African American.
  • You’re over age 35.
  • You had high blood pressure or kidney disease before getting pregnant.
  • You have obesity.
  • You had preeclampsia with another pregnancy.
  • An earlier pregnancy had complications, such as your baby having a low birth weight.

Some health conditions also make preeclampsia more likely, including:

  • Autoimmune diseases, such as lupus
  • Diabetes
  • Gum disease
  • Multiple sclerosis
  • Polycystic ovary syndrome (PCOS)
  • Sickle cell disease
  • Urinary tract infections

You are more likely to have preeclampsia if you use an egg or sperm donor or have in vitro fertilization.

Eclampsia shares some of the same risk factors as preeclampsia, such as:

  • Being pregnant with more than one baby
  • Another family member with preeclampsia or eclampsia
  • A body mass index (BMI) of 30 or more
  • Being younger than 17 or older than 35
  • Living with an autoimmune condition, diabetes, kidney disease, or high blood pressure

The biggest risk factor for eclampsia is preeclampsia. But it’s also important to note that some people who get eclampsia don’t have any risk factors at all. 

“Most women do go into preeclampsia before coming eclamptic. But there are certain women who will present with an eclamptic seizure and then start to have high blood pressure,” says G. Thomas Ruiz, MD, Lead OB/GYN at MemorialCare Orange Coast Medical Center in Fountain Valley, CA.

Experts still aren’t sure what causes these health issues. Some theories focus on:

  • Not enough blood supply to your placenta
  • Your genes 
  • Not getting the right amount of nutrients in the foods you eat
  • Being exposed to toxins 
  • Inflammation inside your body
  • A hormonal imbalance
  • An immune system issue

The early signs of preeclampsia include:

  • High blood pressure
  • High protein levels in your urine (pee)
  • Swelling in your hands, ankles, and feet 
  • Weight gain

These symptoms can be very easy to miss. For instance, you may ignore your swollen ankles because they can be common during pregnancy. Because of that, preeclampsia signs are often first spotted during a regular doctor’s visit.

Other symptoms to watch out for include:

  • Headaches
  • Shortness of breath
  • Pain in your upper belly (on the right side)
  • Blurred vision or seeing dark spots
  • Being very sensitive to light

Eclampsia signs are more severe. They include:

  • Feeling very confused
  • Seizure
  • Coma 

Before a seizure, you could have the same warning signs as preeclampsia, along with:

  • An upset stomach
  • Vomiting
  • Intense headache
  • Not being able to pee or not peeing as much as usual
  • Trouble breathing

If you have any of these symptoms, get to a hospital right away.

At every pregnancy checkup, your doctor will do a physical exam. They’ll test a sample of your pee to look for high levels of protein and check your blood pressure. If they see any signs of preeclampsia, your doctor can order tests such as:

  • Blood tests, to see how well your liver and kidneys are working, and how well your blood is clotting
  • Urine test that checks your pee over 24 hours
  • Ultrasound, to check on your developing baby  

The results can help your doctor understand if you have preeclampsia and if it’s mild or severe.

Mild preeclampsia. Mild preeclampsia means that your blood pressure is higher than 140/90 and you have excess protein in your pee.

Severe preeclampsia. Severe preeclampsia means that at least one of the following applies to you:

  • The top number of your blood pressure is 160 or higher, or the bottom number is 110 or higher at two separate times, at least four hours apart, while you’re on bed rest.
  • You have very high levels of protein in your pee.
  • Your blood test results show signs of liver or kidney damage.
  • You have severe stomach pain.
  • You have other symptoms, such as trouble breathing or seeing.

Your doctor won’t consider eclampsia unless you have a seizure. If so, they could run these same tests to get more information and make a diagnosis.

“Once you start to develop preeclampsia, our goal is to keep you and the baby healthy until you get to 37 weeks, and we can do a delivery of term,” Ruiz says.

If you have mild preeclampsia and are less than 37 weeks along, your doctor may suggest:

Bed rest, to lower your blood pressure. This can also help improve blood flow to your placenta.

More frequent tests. For instance, you could have more blood tests, urine tests, and imaging to keep an eye on your health and your baby’s health.

Medication. Your doctor may prescribe drugs to control your blood pressure or prevent seizures. In some cases, you may be given steroid shots may be given to help your baby’s lungs develop faster. This can be helpful in case you have to deliver your baby early.

If you have severe preeclampsia and are at least 34 weeks into your pregnancy, your doctor may decide that it’s safest for you to have your baby as soon as possible.

At 37 weeks along or later, having your baby right away can treat your preeclampsia. It can also prevent more serious issues for both you and your child.

If you have eclampsia, get to a hospital right away. Doctors there can give you medication to:

  • Stop your seizures
  • Bring your blood pressure down to a healthy range

Your doctor may also need to deliver your baby early, especially if you’re at least 37 weeks pregnant. If not, you risk more serious complications, including stroke, stillbirth, and death.

Sometimes, eclampsia happens after childbirth, too. “Usually, if you’re going to get an eclamptic seizure, it’s going to be within 24 hours of the delivery,” Ruiz says.

Preeclampsia and eclampsia are severe blood pressure issues that happen during pregnancy or soon after you give birth. The causes aren’t yet known. Spotting preeclampsia symptoms can be tricky, as pregnancy itself causes a lot of physical changes. Make sure you go to each of your doctor checkups and let your doctor know if you have any symptoms. If left untreated, preeclampsia and eclampsia can be fatal for you and your baby.

Which is more serious: eclampsia or preeclampsia?

Both preeclampsia and eclampsia should be taken seriously. If ignored, preeclampsia can lead to stroke, coma, organ damage, and eclampsia.

Eclampsia is a medical emergency. If not treated promptly, it can harm both you and your baby.

Can you have eclampsia without preeclampsia?

Usually, eclampsia is a complication of severe preeclampsia. But that isn’t always the case. Some people have seizures without showing any signs of preeclampsia.

How does ultrasound help detect preeclampsia?

An ultrasound lets your doctor see if your baby is growing at a healthy rate. This imaging test can give them an idea of your baby’s weight. It can also confirm that there’s enough amniotic fluid (a protective liquid) in your uterus.

A certain ultrasound technique called uterine artery doppler can help screen you for preeclampsia as early as the first trimester. It looks at how well blood flows into your uterus. If your doctor sees any issues, they can monitor you more closely during your pregnancy. They may also decide to take other steps to keep you and your baby safe. For instance, they may tell you to take a low-dose aspirin to help prevent preeclampsia.