Loading icon
Press enter or spacebar to select a desired language.
Health Information Center

Hyperemesis Gravidarum

  • Cynthia M. Johnson, MA
Publication Type:


Hyperemesis Gravidarum

(Severe Morning Sickness; Persistent Vomiting of Pregnancy; HG)


Hyperemesis gravidarum (HG) is severe nausea and vomiting during pregnancy. It is not common.


The cause is not known. There are many thoughts about what may cause HG, such as:

The Brain May Be the Cause of Nausea.

Brainstem and brainhttp://services.epnet.com/getimage.aspx?imageiid=67536753brainstem_pineal.jpgBrainstem and brainNULLjpgBrainstem and brainNULL\\hgfiler01a\intellect\images\brainstem_pineal.jpgNULL42NULL2008-01-10261400Copyright © Nucleus Medical Media, Inc.

Risk Factors

HG is more common in young pregnant people. It is also more common in pregnant people who are Asian or Black.

Other things that may raise the risk are:

  • HG during past pregnancies
  • Past molar pregnancy—a growth of abnormal tissue in the womb
  • A parent or sibling with HG
  • A pregnancy of twins or more babies
  • First time pregnancy
  • Having some health problems, such as migraines or motion sickness


A person with HG may have:

  • Nausea and vomiting in early pregnancy
  • Weight loss
  • Lightheadedness and fainting


The doctor will ask about symptoms and health history. A physical exam will be done. Blood and urine tests may also be done.


The goal of treatment is to manage symptoms to prevent weight loss and dehydration. Ways to treat HG are:

  • Lifestyle changes, such as eating lots of small meals of bland, dry, high-protein foods
  • Anti-nausea medicine
  • Vitamin B6 to ease nausea


The risk of HG may be lowered by taking prenatal vitamins for 1 month before becoming pregnant.





  • Committee on Practice Bulletins-Obstetrics. ACOG practice bulletin 189: nausea and vomiting of pregnancy. Obstet Gynecol, 2018; 131 (1): e15-e30.
  • Hyperemesis gravidarum. American Pregnancy Association website. Available at: https://www.americanpregnancy.org/healthy-pregnancy/pregnancy-complications/hyperemesis-gravidarum.
  • Nausea and vomiting in pregnancy. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/nausea-and-vomiting-in-pregnancy.
  • Severe vomiting in pregnancy. NHS website. Available at: https://www.nhs.uk/pregnancy/related-conditions/complications/severe-vomiting.


  • Marcin Chwistek, MD
Last Updated:

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.