What Are the Differences Between Mild and Severe Preeclampsia?

Pregnancy is a time of huge physical and emotional change, and can come with some pretty amazing perks—glowing skin and shiny hair, anyone? But side effects like preeclampsia aren’t so welcome.

Preeclampsia is a serious pregnancy condition that can affect every internal organ, says the American College of Obstetricians and Gynecologists (ACOG). This potentially dangerous condition is classified as either mild or severe. Mild preeclampsia is characterized by high blood pressure and protein in the urine. Severe preeclampsia has those symptoms as well as signs of damage to the liver or kidneys.

Preeclampsia usually starts during the second half of pregnancy (after 20 weeks), and when it occurs before 34 weeks it’s known as early-onset preeclampsia. Here’s what you need to know about mild and severe forms of preeclampsia, how the conditions are treated, and when to address any concerns with your healthcare provider. 

What Is Preeclampsia?

Up to 8% of pregnancies are complicated by preeclampsia and related hypertensive disorders, per the Preeclampsia Foundation. The common signs and symptoms are high blood pressure (medically known as hypertension), high levels of protein in the urine, and swelling of the feet/ankles, legs, hands, and face, says Sherry Ross, MD, OB/GYN and women’s health expert at Providence Saint John’s Health Center in Santa Monica, Calif. 

Although preeclampsia is brought on by pregnancy and the signs and symptoms usually go away after the baby is born, it can occur postpartum, says Christina Buchanan, MD, OB/GYN with Providence St. Jude Medical Center in Orange County, Calif. 

Symptoms of Mild Preeclampsia

Individuals with mild preeclampsia often have no symptoms. “The first sign of preeclampsia may be elevated blood pressure at the doctor’s office along with protein in the urine,” says Dr. Buchanan. 

Specifically, new onset of blood pressure greater than 140/90 and urine protein of greater than or equal to 300 mg/24 hours can be a sign of mild preeclampsia, says Dr. Ross. 

Preeclampsia doesn’t necessarily require hospitalization. “Mild preeclampsia can be monitored closely and the patient can be on home bed-rest with frequent visits to the obstetrician until the baby is ready to be delivered,” says Dr. Ross. 

Symptoms of Severe Preeclampsia

When a pregnant person's blood pressure is greater than 160/110 and urine proteinuria is 3+ or greater on a urine dipstick, a diagnosis of severe preeclampsia may be made, says Dr. Ross. 

Other symptoms of severe preeclampsia include poor urine output, right upper abdomen pain, abnormal liver function testing, low platelets, visual changes, pulmonary edema (when fluid collects in the numerous air sacs in the lungs, making it difficult to breathe), and poor fetal growth.

Dr. Buchanan notes that sometimes individuals with severe preeclampsia have no symptoms, but may have severely elevated blood pressures or abnormalities noted on blood work. In the most severe cases of preeclampsia, the only treatment is delivery of the baby, regardless of gestational age.

When to Call a Healthcare Provider

Whether you’ve been diagnosed with mild or severe preeclampsia, there are certain symptoms that require medical attention. 

“If a pregnant person with preeclampsia has a headache that will not go away, is seeing spots or experiences changes in eyesight, has pain in the upper abdomen or shoulder, persistent nausea and vomiting, or difficulty breathing, they should immediately follow up with a healthcare provider or emergency services,” says Dr. Ross. 

If you’re pregnant and have high blood pressure or have been diagnosed with preeclampsia, Dr. Buchanan advises keeping a close eye on your blood pressure at home. Most pharmacies sell blood pressure monitors, which you can calibrate with the one used in your caregiver's office.

Try to take your blood pressure at the same time each day and in the same position, and keep a record of the results. Share your log with your caregiver at each visit, and don't wait until the next visit if you notice a significant rise in your blood pressure.

If you’re at least 34 weeks pregnant, your OB/GYN may advise delivering the baby as long as your condition is stable, according to ACOG. 

If you’re not at 34 weeks yet and your condition is stable, it may be possible to delay delivery. Even if it’s just for a few days, it can be long enough to administer corticosteroids to help the baby’s lungs mature. During this time, other meds can be taken to lower blood pressure and help to prevent seizures. 

A Word From Verywell

Proper prenatal care is essential to ensure the early warning signs of preeclampsia are picked up, so don’t miss your appointments. At every visit, your caregiver will check your weight and your blood pressure and test your urine for protein. If any of these tests don't take place, don't be scared to ask why.

Mild preeclampsia can be treated in the hospital or as an outpatient, while severe preeclampsia is usually treated in the hospital. The most important thing is to get medical help as soon as possible to avoid complications for both you and your baby.