High Blood Pressure in Pregnancy: What the Different Diagnoses Mean

High blood pressure is one of the most common complications I see during pregnancy—both in the office and on the labor and delivery floor. But “high blood pressure in pregnancy” is not just one diagnosis. It includes several conditions that can overlap, progress, and require different levels of monitoring.

In my new video, I walk through the diagnostic criteria for chronic hypertension, gestational hypertension, preeclampsia, preeclampsia with severe features, HELLP syndrome, and eclampsia.

Watch: High Blood Pressure In Pregnancy—When Is It Preeclampsia?

What counts as high blood pressure during pregnancy?

A blood pressure reading has two numbers:

• Systolic blood pressure is the top number. It measures the pressure in your arteries when your heart contracts.
• Diastolic blood pressure is the bottom number. It measures the pressure when your heart relaxes between beats.

During pregnancy, a blood pressure of 140/90 mm Hg or higher is considered elevated. A diagnosis is typically based on repeat readings—not one isolated number. Severe-range blood pressure is a systolic pressure of 160 or higher, a diastolic pressure of 110 or higher, or both.

The timing of a high reading and whether there are other symptoms, urine findings, or lab abnormalities help determine the diagnosis.

Chronic hypertension

Chronic hypertension means high blood pressure that:

• Was present before pregnancy,
• Was diagnosed before 20 weeks of pregnancy, or
• Persists after pregnancy.

Blood pressure normally tends to decrease during the first half of pregnancy. That is why high readings before 20 weeks often suggest that the hypertension was present before pregnancy, even if it had not been diagnosed yet.

Someone with chronic hypertension can also develop preeclampsia later in pregnancy. This is called superimposed preeclampsia.

Gestational hypertension

Gestational hypertension is new high blood pressure that begins after 20 weeks of pregnancy in someone whose blood pressure was previously normal.

The key distinction is that gestational hypertension involves elevated blood pressure without the signs of organ dysfunction used to diagnose preeclampsia. Because the condition can progress, your care team will usually monitor your blood pressure, symptoms, urine, bloodwork, and the baby more closely.

If blood pressure reaches the severe range, the situation requires prompt medical evaluation.

Preeclampsia

Preeclampsia is a pregnancy-related high blood pressure disorder that usually develops after 20 weeks, although it can also occur after delivery.

Many people associate preeclampsia with high blood pressure plus protein in the urine. That is a classic presentation—but protein in the urine is not required if there are other signs that the condition is affecting the body.

Preeclampsia may be diagnosed when new high blood pressure occurs along with one or more findings such as:

• New protein in the urine,
• A low platelet count,
• Abnormal liver function,
• Abnormal kidney function,
• Fluid in the lungs,
• A severe headache that does not go away,
• New vision changes, or
• Significant upper abdominal pain, especially on the right side.

Some people with preeclampsia feel completely well. That is one reason routine prenatal blood pressure checks are so important.

Preeclampsia with severe features

Preeclampsia with severe features means there are signs that the disease is more advanced or poses a greater risk.

Severe features can include:

• Blood pressure of 160/110 mm Hg or higher,
• Severe or persistent headache,
• New vision changes,
• Significant right upper abdominal pain,
• Fluid in the lungs or difficulty breathing,
• Very low platelets, or
• Significant liver or kidney abnormalities.

Preeclampsia with severe features often requires hospital evaluation and careful decisions about medication, seizure prevention, monitoring, and timing of delivery.

HELLP syndrome

HELLP syndrome is a severe pregnancy complication defined by a specific pattern of blood abnormalities:

• Hemolysis: red blood cells are breaking down,
• ELevated Liver enzymes: a sign of liver injury, and
• LP: low platelets, which can affect blood clotting.

HELLP is generally considered part of the preeclampsia spectrum. Common symptoms can include pain in the right upper abdomen, nausea or vomiting, headache, and feeling profoundly unwell or unusually fatigued.

Most people with HELLP have high blood pressure, but it can occasionally occur without a clearly elevated blood pressure. Symptoms and laboratory testing both matter.

Eclampsia

Eclampsia is diagnosed when a person with preeclampsia develops seizures that cannot be explained by another cause. It is a medical emergency.

The word can be confusing: preeclampsia does not simply mean “before eclampsia,” and most people with preeclampsia do not have a seizure. But recognizing and treating severe disease is essential to reduce that risk.

When should you call your healthcare team?

Contact your obstetric care team right away if you have a high blood pressure reading or symptoms that could be concerning for preeclampsia, including:

• A severe headache that does not go away,
• New blurry vision, flashing lights, spots, or loss of vision,
• Significant pain in the upper abdomen or under the right ribs,
• Sudden shortness of breath or difficulty breathing,
• Sudden swelling of the face or hands, or
• A strong sense that something is not right.

Preeclampsia can also develop after birth. New high blood pressure or warning symptoms during the postpartum period deserve prompt attention. Severe symptoms, a seizure, trouble breathing, chest pain, or severe-range blood pressure require emergency medical care.

High blood pressure diagnoses in pregnancy can sound like a blur of similar terms. The most important distinctions are when the blood pressure began, how high it is, and whether there are symptoms or signs that other organs are being affected.

If you have concerns about your blood pressure or any symptoms discussed here, please contact your own healthcare professional. This post is for general education and is not a substitute for individualized medical advice.

Sources and further reading

• American College of Obstetricians and Gynecologists: Preeclampsia and High Blood Pressure During Pregnancy
• Centers for Disease Control and Prevention: High Blood Pressure During Pregnancy