What Is Hyperemesis Gravidarum?

Severe Nausea and Vomiting During Pregnancy

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Hyperemesis gravidarum is extreme, persistent nausea and vomiting during pregnancy. It is not the same as morning sickness, which refers to mild nausea and vomiting that often occur in the first three months of pregnancy. Hyperemesis gravidarum is less common and more severe. It can occur during any pregnancy, but some people, such as those who had this condition in previous pregnancies, may be more at risk.

People with hyperemesis gravidarum may vomit more than three to four times a day. They may vomit so much that they feel dizzy and lightheaded. This condition can lead to weight loss, dehydration, and electrolyte imbalance.

HG pregnancy

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Symptoms of Hyperemesis Gravidarum

About 70% of people have nausea and vomiting during pregnancy, often in early pregnancy and most often in the morning—hence the name "morning sickness." Hyperemesis gravidarum, a more severe form of nausea and vomiting, is estimated to affect 0.3% to 10.8% of pregnancies. This condition is the most severe form of nausea and vomiting during pregnancy, and it often begins before the 20th week of pregnancy.

Symptoms of hyperemesis gravidarum are similar to those of morning sickness, but they are more severe. They include:

  • Severe nausea and vomiting
  • Weight loss of 5% or more
  • Signs of dehydration such as dark urine, dry skin, weakness, lightheadedness, or fainting
  • Vitamin and mineral deficiencies
  • Increased heart rate (tachycardia)
  • Increased salivation (ptyalism)
  • Constipation

The severity of this condition can result in a number of complications, including:

  • Depression and anxiety
  • Damage to the esophagus from vomiting and reflux
  • Delayed gastric emptying (gastroparesis)
  • Neurological changes like encephalopathy, vision changes, confusion, and delirium

Hyperemesis Gravidarum Can Affect Infants Too

Some complications that may occur in babies as a result of hyperemesis gravidarum include:

  • Lower birth weight
  • Smaller size
  • Increased risk of developmental delays


The exact cause of hyperemesis gravidarum isn't clear, but some evidence suggests that hormones may play a role:

  • Human chorionic gonadotropin (hCG): This hormone is released by the placenta. Symptoms of hyperemesis gravidarum were worst when the blood level of this hormone peaked during pregnancy in one study.
  • GDF15: This hormone affects appetite and taste, and its receptor gene is located in the part of the brain that controls vomiting. High GDF15 levels have been found in people with hyperemesis gravidarum, suggesting a genetic link.

Risk Factors

People who have the following conditions or characteristics may be more prone to developing hyperemesis gravidarum:

  • Hydatidiform mole (a rare mass that grows in the uterus at the beginning of pregnancy)
  • Pregnancy with twins or more babies
  • Previous pregnancies with hyperemesis gravidarum
  • Family history of hyperemesis gravidarum
  • Motion sickness
  • Being a first-time mother
  • Being overweight


Diagnosis of hyperemesis gravidarum is based primarily on the severity of symptoms. Typically, signs that pregnancy nausea and vomiting are progressing to hyperemesis gravidarum appear between the fourth and sixth week of pregnancy. Symptoms may improve between the 14th and 20th week. About 20% of people will have this condition for the duration of their pregnancies.

Your healthcare provider will ask you about your symptoms and perform a physical exam to rule out other potential causes of your symptoms. Lab tests may be done to monitor your health, especially to monitor your fluid and electrolyte levels. Your healthcare provider may order blood or urine tests to monitor the following:

  • Increased ketones
  • Increased specific gravity or urine
  • Increased blood urea nitrogen
  • Electrolyte imbalances
  • Vitamin deficiencies
  • Increased liver enzymes or bilirubin levels
  • Abnormal thyroid or parathyroid levels
  • Increased hematocrit

Abnormal results from these tests could indicate dehydration, malnutrition, or deficiencies. A pregnancy ultrasound will be done to see if you are carrying twins or more babies and if you have a hydatidiform mole.


Treatment focuses on alleviating severe symptoms in many cases. This usually involves hospitalization and the administration of intravenous fluids and nutrients to make up for those lost through vomiting. In the most severe cases, complex, balanced solutions of nutrients have to be given through an IV throughout pregnancy. This is called total parenteral nutrition.

If nausea and vomiting continue after fluid and nutrient replacement, antiemetics and other medications may be used, including:

  • Doxylamine or pyridoxine
  • Diphenhydramine
  • Metoclopramide
  • Ondansetron
  • Corticosteroids
  • Antacids
  • Antihistamines
  • Promethazine
  • Compazine
  • Mirtazapine

There are also holistic methods, treatments, and therapies that may help alleviate the symptoms of hyperemesis gravidarum. These might include a pressure-point wristband similar to those used for motion sickness, vitamin B6 supplement, and ginger supplement. Nausea and vomiting may also be treated with dry foods such as crackers, and small, frequent meals.

When to Call Your Healthcare Provider

Call your healthcare provider if you are pregnant and have severe nausea and vomiting or if you have any of the following symptoms:

  • Signs of dehydration
  • Unable to tolerate any fluids for over 12 hours
  • Lightheadedness or dizziness
  • Blood in the vomit
  • Abdominal pain
  • Weight loss of more than 5 pounds


A number of considerations are key to managing hyperemesis gravidarum:

  • Treatment is individualized and no one medication combination or therapy works for everyone.
  • Symptoms cannot be cured completely, only reduced.
  • You may not be able to take oral medications, and they may have to be given in other ways.
  • Medications may target other issues beyond nausea.

You may want to avoid certain things that can trigger nausea and vomiting, such as:

  • Certain noises and sounds, even the radio or TV
  • Bright or blinking lights
  • Toothpaste
  • Smells such as perfume and scented bathing and grooming products
  • Pressure on your stomach (wear loose-fitting clothes)
  • Riding in a car
  • Taking showers

Take advantage of the times you feel better to eat and drink, and increase fluid intake during times of the day when you don't feel nauseated. Seltzer, ginger ale, or other sparkling drinks may help.

Psychological and emotional support are key too. People who suffer from hyperemesis gravidarum in their pregnancy may have feelings of anxiety or depression, guilt, or trauma. A compassionate and caring clinician is essential, as are support and education for family and other support members.

A Word From Verywell

Nausea and vomiting may be usual pregnancy symptoms for many people, but for some, the symptoms can be extreme and lead to serious complications. Hyperemesis gravidarum isn't just an exaggeration of a normal pregnancy problem. It's a serious condition that could result in hospitalization, severe illness, and pregnancy loss. People who have this condition may need to try a variety of medications and treatments to find relief, and having a strong support system in place is crucial to coping.

9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  6. Fejzo MS, Arzy D, Tian R, MacGibbon KW, Mullin PM. Evidence GDF15 Plays a Role in Familial and Recurrent Hyperemesis Gravidarum. Geburtshilfe Frauenheilkd. 2018 Sep;78(9):866-870. doi:10.1055/a-0661-0287

  7. Cleveland Clinic. Hyperemesis gravidarum.

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  9. MedlinePlus. Hyperemesis gravidarum.

By Rachael Zimlich, BSN, RN
Rachael is a freelance healthcare writer and critical care nurse based near Cleveland, Ohio.