Everyone says nausea is just part of pregnancy. But what you are experiencing is something else entirely. You cannot keep any fluids down. You cannot get out of bed. You wonder if it will ever end.

Hyperemesis gravidarum (HG) is not ordinary morning sickness. It is a serious medical condition affecting 0.3–2% of all pregnancies. And you deserve to be taken seriously.

What is hyperemesis gravidarum?

Hyperemesis gravidarum is extreme nausea and vomiting during pregnancy that leads to dehydration, weight loss, and significant impairment of daily function. It is the most severe form of pregnancy nausea and requires medical treatment.

The difference between ordinary morning sickness and HG:

	Ordinary nausea	Hyperemesis gravidarum
How common	80–90% of pregnancies	0.3–2% of pregnancies
Vomiting	Occasional	Many times daily
Food/drink	Able to eat something	Little or nothing
Weight loss	Little or none	Over 5% of body weight
Dehydration	No	Often
Hospital	Rarely needed	Often needed
Function level	Reduced but manageable	Severely impaired, bedridden

HG is not an overreaction to ordinary nausea. It is a medical condition with physiological causes. You need treatment — not to "push through it."

Symptoms — when is it more than morning sickness?

Contact your doctor or midwife if you experience one or more of these symptoms:

Vomiting

You are vomiting more than 3–4 times a day
You cannot keep water or other fluids down for more than 12–24 hours
Vomit contains bile or blood

Dehydration

Dark, concentrated urine
Urinating fewer than 3 times a day
Dry mouth and lips
Dizziness when standing up
Headache

Weight loss

You have lost more than 5% of your pre-pregnancy body weight
For someone who weighed 154 lbs before pregnancy, that means about 7–8 lbs or more

Functional impairment

You are unable to work
You are unable to care for yourself or other children
You are in bed for most of the day

Other signs

Excessive saliva production (ptyalism)
Sensitivity to smells, light, and movement
Exhaustion and apathy
Difficulty concentrating

You do not need to have all of these symptoms to have HG. If you are vomiting so frequently that you cannot keep fluids down, contact a doctor regardless.

Causes

The exact cause of HG is not fully understood, but research points to several factors:

Hormonal factors

hCG hormone — Levels are often higher in people with HG. hCG rises steeply in the first trimester, which corresponds with the worst period of nausea
GDF15 — A protein produced by the placenta. Research published in Nature (2024) shows that sensitivity to GDF15 plays a central role in triggering nausea

Genetic factors

HG has a hereditary component. If your mother or sister had HG, your risk is higher.

Other risk factors

Twin pregnancy (higher hormone levels)
HG in a previous pregnancy (recurrence risk 15–80%)
History of migraines
Motion sickness
First pregnancy

Treatment

Treatment for HG follows guidelines from professional obstetric bodies including ACOG and the Society of Obstetricians and Gynaecologists of Canada, and includes both outpatient management and hospitalization.

Step 1: At home with support

For mild to moderate HG, you may be managed at home:

Anti-nausea medications (see below)
Small, frequent meals — eat what you can, when you can
Fluids — small sips often, ice chips, popsicles
Rest — listen to your body
Take sick leave — HG is a valid medical reason to be off work

Step 2: Outpatient IV fluids

Some hospitals and urgent care centers can give intravenous (IV) fluids without admission:

You come in for a few hours
Receive saline and glucose intravenously
Anti-nausea medication may be given by injection
You go home afterward

Step 3: Hospital admission

With severe dehydration or insufficient response to outpatient treatment, hospitalization is needed:

IV fluids — to correct dehydration and electrolyte imbalances
IV anti-nausea medication — more effective than tablets
Vitamin supplementation — especially thiamine (vitamin B1) to prevent deficiency
Nutritional support — nutritional drinks; nasogastric tube feeding in rare cases
Rest — quiet room, dimmed lights
Monitoring blood tests — electrolytes, kidney and liver function

Do not wait until you are completely exhausted. The earlier you seek help, the easier dehydration and nutritional deficiencies are to treat. Contact your doctor, midwife, or urgent care if you cannot keep fluids down.

Medications for HG

Several medications are considered safe to use for severe pregnancy nausea:

First-line options

Doxylamine/B6 (Diclegis/Bonjesta) — FDA-approved for pregnancy nausea. A combination of an antihistamine and vitamin B6
Promethazine or dimenhydrinate — Antihistamines that reduce nausea; may cause drowsiness
Metoclopramide — Reduces nausea and promotes stomach emptying

When first-line options are insufficient

Ondansetron (Zofran) — A potent anti-nausea medication originally developed for chemotherapy. Used for severe HG when other medications have not helped. ACOG notes it appears safe in the second and third trimester, but advises caution in the first trimester (weeks 1–12) unless strictly necessary
Prochlorperazine — An alternative anti-nausea medication

Supplements

Vitamin B6 (pyridoxine) — May have mild anti-nausea effect
Thiamine (vitamin B1) — Important to prevent Wernicke's encephalopathy with prolonged vomiting

Never start medications without speaking to your doctor. Dosing must be tailored to your situation, and some medications should be avoided at certain stages of pregnancy.

Is HG dangerous for the baby?

The short answer: with proper treatment, no.

Mild to moderate HG with adequate treatment rarely affects the baby
Severe, untreated HG with significant weight loss can lead to low birth weight
The baby takes what it needs from the mother's reserves — it is the mother who suffers most

Research shows that people with HG who receive treatment have babies just as healthy as others. The most important thing is that you get the help you need.

Mental health and HG

HG is an enormous strain — not just physically, but mentally. Many people with HG experience:

Depression — isolation, loss of control, constant discomfort
Anxiety — fear that something is wrong with the baby, fear of future pregnancies
Loneliness — friends and family don't always understand the severity
Guilt — feeling like you are failing at pregnancy, not being happy enough
Grief — over weeks or months lost to illness, over work absences
Thoughts of ending the pregnancy — some people with severe HG consider this. It is a consequence of the condition, not a sign that you are a bad parent

Many people with HG describe it as the hardest period of their life. If you recognize yourself in this, you are not alone. Talk to your midwife, doctor, or a mental health professional about the psychological burden. Crisis lines like the Postpartum Support International helpline (1-800-944-4773) can also be a resource.

Partners and family members

HG affects the whole family. Partners may feel helpless and worn out. Older siblings can struggle when a parent is unwell. Tips for partners:

Take the sick person seriously — HG cannot be "fixed" by willpower
Take over household tasks, cooking, and childcare
Attend medical appointments
Be patient — this takes time
Seek support yourself — talk to friends, family, or your own doctor

When does it end?

For most people, HG eases gradually:

Weeks 14–16: Some begin to improve
Week 20: Significant improvement for most
Throughout pregnancy: 10–20% have symptoms until delivery

It is common for HG to ease in waves — you may have some good days followed by a relapse. Do not lose heart.

Your rights

As a pregnant person with HG, you have rights:

Sick leave — Your doctor or midwife can certify you as unfit for work. HG is a valid medical reason
Workplace accommodations — Your employer is obligated to explore reasonable accommodations
Hospital treatment — You are entitled to necessary medical care
Privacy — You do not need to disclose your diagnosis to your employer, only that you are on medical leave

Future pregnancies after HG

The risk of HG in a future pregnancy is elevated (15–80%), but that does not mean you are certain to go through it again. Talk to your doctor about:

Preventive medication starting early in the next pregnancy
Closer monitoring from the beginning
A plan for early intervention if symptoms arise

Frequently asked questions

Is HG the same as morning sickness?

No. Ordinary morning sickness is unpleasant but manageable. HG is a medical condition involving vomiting many times a day, dehydration, and weight loss. It requires medical treatment.

Can I take anti-nausea medications during pregnancy?

Yes, several medications are considered safe during pregnancy. Doxylamine/B6 (Diclegis) is a common first-line option. Stronger medications like ondansetron require a prescription. Talk to your doctor.

Does HG mean something is wrong with the baby?

No. HG is a condition affecting the mother, not the baby. The baby is usually not affected when treatment is adequate. HG is actually associated with a lower risk of miscarriage.

Can I be admitted to hospital for HG?

Yes, absolutely. Hospitalization is appropriate with severe dehydration, electrolyte disturbances, or insufficient response to outpatient treatment. You are entitled to necessary medical care.

Will HG come back in a future pregnancy?

The risk is elevated, but many people have a milder course in subsequent pregnancies. Preventive medications can be started early.

Is there anything I can do to prevent HG?

It is difficult to prevent HG since the causes are partly genetic and hormonal. Some studies suggest that starting prenatal vitamins with B vitamins before conception may reduce the risk somewhat.

Hyperemesis Gravidarum: Severe Pregnancy Nausea