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Nausea & GI Call your provider

Hyperemesis gravidarum

Also known as Severe nausea and vomiting of pregnancy, HG. Usually 4–16 weeks, peaking around 9–13 weeks.

This is nausea and vomiting that has crossed a line: severe, relentless, well beyond ordinary morning sickness. The marker is vomiting bad enough to leave you dehydrated and down more than 5% of your pre-pregnancy weight. If you cannot keep food or fluids down, are losing weight, and feel wrung out, you are not being dramatic and do not have to tough it out. Hyperemesis gravidarum is a real medical condition with real treatments, and getting help early keeps it from spiraling.

Know the warning signs When to call a provider
How common
0.3% to 3% of pregnancies
The severe end of the spectrum; about 7 in 10 pregnancies have some nausea.
When
Early pregnancy
Starts around 4 to 6 weeks, peaks near 9 to 13 weeks.
Urgency
Call your provider
Not keeping fluids down or making little urine needs prompt care.
Outlook
Good with treatment
It usually eases by mid-pregnancy, and outcomes are generally favorable.

Understanding it

What is hyperemesis gravidarum?

Most pregnancies bring some nausea; hyperemesis gravidarum is a different animal, severe, persistent vomiting that leaves you dehydrated, unable to keep fluids down, and losing weight, typically more than 5% of your pre-pregnancy weight. Affecting 0.3% to 3% of pregnancies, it can be debilitating, keeping people out of work and, at its worst, in the hospital.

It tends to begin around 4 to 6 weeks, peak near 9 to 13 weeks, and ease by 16 to 20 weeks, though for a minority it lingers to delivery. The timing tracks hCG, the pregnancy hormone that rises fastest in these weeks.

The cause is still being worked out, but it involves how your body responds to hCG and to a hormone called GDF15, with a clear genetic thread: if your mother or sister had it, or you did before, you are more likely to as well. What it is not is weakness, attitude, or anything you brought on. People are still told it is psychological, and that is both untrue and unhelpful.

The key message is that it is treatable. A stepwise ladder runs from vitamin B6 and anti-nausea medicines to IV fluids and, when needed, hospital care. Starting early keeps symptoms from escalating, and with support the outlook for you and your baby is generally good.

Symptoms

What are the symptoms?

The hallmark is nausea and vomiting severe enough that you cannot keep food and fluids down, leading to weight loss and dehydration. The emergency signs are the signs of dehydration and of not getting enough nutrition.

Early signs

  • Severe, persistent nausea and near-constant vomiting
  • Losing more than 5% of your pre-pregnancy weight
  • Producing much more saliva than usual
  • Feeling faint or lightheaded
  • Not being able to keep down food or even sips of water

Emergency signs — call 911

  • Not being able to keep any fluids down for 12 hours or more
  • Little or no urine, or urine that is very dark
  • Feeling dizzy or faint when you stand, or a racing heart
  • Vomiting blood
  • Confusion or severe weakness, which can signal a vitamin (thiamine) deficiency

Why it matters

Risks to you and baby

Dehydration and electrolyte imbalance

Persistent vomiting drains fluids and key salts like potassium and sodium, which is why IV fluids are often needed. Unchecked, this is the main danger and the reason not to wait it out at home.

Thiamine (vitamin B1) deficiency

Prolonged vomiting can deplete thiamine, and giving sugar-containing fluids without replacing it first can trigger a serious brain condition, Wernicke encephalopathy. That is why hospitals give thiamine before any dextrose.

Weight loss and nutrition

Significant weight loss is part of the definition. With treatment your baby usually draws on your reserves and grows normally; severe, untreated cases can be linked to lower birth weight.

The toll on you

Months of relentless vomiting is exhausting and isolating, and it is linked to anxiety and depression. Your suffering is real and deserves treatment; support is part of care, not a luxury.

Your baby's outlook

With appropriate treatment, most babies are born healthy. The condition itself does not cause birth defects.

How it's found

How is it diagnosed?

Hyperemesis is a clinical diagnosis, based on severe vomiting, weight loss, and dehydration, after ruling out other causes. A few tests confirm the picture and check for related issues.

Weight and history

Loss of more than 5% of pre-pregnancy weight, with an inability to keep food and fluids down, is central to the diagnosis.

Urine and blood tests

Ketones in the urine reflect the body burning fat for fuel, and blood tests reveal dehydration and low electrolytes like potassium and sodium.

Ultrasound

Confirms the pregnancy and checks for twins or a molar pregnancy, both of which raise hCG and can cause severe vomiting.

Thyroid tests

High hCG can produce a temporary overactive-thyroid picture, usually mild, self-limited, and not needing thyroid medication.

When nausea and vomiting are severe enough to cause weight loss or dehydration, beyond the milder nausea most pregnancies bring.

Treatment

How is it managed?

Treatment follows a ladder, adding steps until symptoms are controlled. The aim is to keep you hydrated and nourished and make you functional again, not just barely coping.

Treatment paths

Simple measures come first: small, frequent, bland meals, avoiding triggers, sometimes ginger. Vitamin B6 (pyridoxine), often combined with the antihistamine doxylamine, is the usual first medication. If that is not enough, antiemetics such as ondansetron, metoclopramide, promethazine, or prochlorperazine are added. When you cannot stay hydrated, IV fluids are given, and some people need a hospital stay. Rarely, nutrition is delivered through a tube or a vein.

Medication

A doxylamine and pyridoxine combination (Diclegis, or extended-release Bonjesta) is FDA-approved for nausea and vomiting of pregnancy, with additional antiemetics as needed. In the hospital, thiamine is given before any sugar-containing fluids to prevent a serious vitamin deficiency.

Monitoring

Your weight, hydration, urine ketones, and electrolytes are followed, and treatment is stepped up or down as you respond.

Can it recur?

Often, yes. Hyperemesis recurs in roughly a quarter of future pregnancies. Knowing that lets you plan ahead and start treatment at the first signs next time.

What you can do

Can it be prevented?

  • It usually cannot be prevented

    Because it is driven by hormones and genetics, hyperemesis cannot be reliably avoided. A prenatal multivitamin around conception may lower the odds of more severe nausea.

  • Treat early if you have had it before

    If a past pregnancy brought hyperemesis, talk with your provider before or early in the next about starting anti-nausea treatment at the first symptoms.

Who is more at risk

Risk factors

Hyperemesis in a past pregnancy
The strongest single risk factor.
Recurs in about 24% of later pregnancies
Family history
A mother or sister who had hyperemesis raises your risk.
Up to a threefold increase
A high-hCG pregnancy
Carrying twins or more, or a molar pregnancy, produces higher hCG and more severe nausea.
First pregnancy and carrying a girl
Both are associated with a somewhat higher chance of hyperemesis.
A history of motion sickness or migraines
People prone to motion sickness, or to nausea with migraines, are more likely to develop it.

Do not wait

When to call your provider or 911

  • Seek care promptly if you cannot keep any fluids down for 12 hours or more, are making little or very dark urine, or feel dizzy or faint when you stand.
  • Call right away if you are vomiting blood, or feel confused or severely weak.
  • Call if you are losing weight, or if nausea and vomiting keep you from eating, drinking, working, or caring for yourself.
  • If you have had hyperemesis before, call early this pregnancy so treatment can start before symptoms escalate.
  • Reach out if the emotional weight of being this sick feels like too much; that is part of the illness and part of what care addresses.

Talking to your team

Questions to ask your provider

  • Which medications are safe and effective for me, and in what order?
  • At what point would I need IV fluids or a hospital stay?
  • Should I be checked for twins or a molar pregnancy?
  • How will we track my weight, hydration, and electrolytes?
  • What can I safely eat and drink to hold on to calories and fluids?
  • If I had this before, can we start treatment earlier this time?
  • Where can I find support from others who understand this?

Keep reading

More on hyperemesis gravidarum

All pregnancy guides articles

Good to Know

Hyperemesis gravidarum FAQs

Common questions about hyperemesis gravidarum, answered.

Is this just really bad morning sickness?

No. Ordinary morning sickness does not cause dehydration or weight loss. Hyperemesis means vomiting severe enough to lose more than 5% of your pre-pregnancy weight and become dehydrated, and it deserves treatment.

Are the anti-nausea medications safe for my baby?

The first-line vitamin B6 and doxylamine combination is among the best-studied treatments in pregnancy and considered safe. Other antiemetics are used when needed. Severe dehydration and undernutrition carry their own risks, which is why treating matters.

Will I be this sick the whole pregnancy?

Usually not. Symptoms typically peak around 9 to 13 weeks and ease by 16 to 20 weeks. A minority last longer, sometimes to delivery, but treatment still helps.

Is my baby getting enough nutrition if I can't eat?

In most cases, yes. Early on your baby's needs are small and your body draws on its reserves. With treatment to keep you hydrated, and nutritional support if needed, babies usually grow normally.

Why do I need IV fluids or a hospital stay?

When you cannot keep fluids down you become dehydrated, lose salts, and burn fat (seen as ketones). IV fluids restore you quickly, and a short stay lets your team control the vomiting.

Will it happen again in my next pregnancy?

About a one-in-four chance. Tell your provider your history so you can treat at the first symptoms next time, which often keeps it milder.

Is this in my head or my fault?

No. Hyperemesis gravidarum is a physical condition tied to pregnancy hormones and genetics, not stress or attitude. Anyone who suggests otherwise is mistaken, and it should never delay treatment.

Is there anything I can try at home?

Small, frequent, bland meals, sipping fluids, ginger, and avoiding trigger smells help at the edges. But if you are losing weight or cannot keep fluids down, medication and fluids are the next step.

Medically Reviewed · Updated

Reviewed by Dr. Grace Lin, MD, FACOG · OB-GYN

Obstetrician-gynecologist focused on reproductive and sexual health for women: pregnancy, BV, yeast, trichomoniasis and HPV/cervical screening. Our editorial guidelines →

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