Pregnancy

Hyperemesis Gravidarum: Symptoms, Treatment and How It Differs From Morning Sickness

By the Find Her Doctor editorial team · Updated November 1, 2026 · 6 min read

Hyperemesis gravidarum (HG) is severe, persistent nausea and vomiting in pregnancy that leads to dehydration, weight loss and sometimes low potassium or other chemical imbalances. It's much less common than ordinary morning sickness, and it's a real medical condition, not a lack of willpower. It's treatable, and getting care early helps both you and your baby.

If you're reading this from the bathroom floor, here's the most useful sentence on this page: if you can't keep fluids down for 24 hours, call your provider today. You don't need to earn treatment by suffering longer.

Is this morning sickness or HG?

For milder symptoms, see our guide to morning sickness.

What are the symptoms of hyperemesis gravidarum?

HG usually starts in the first trimester. Common signs:

• Vomiting many times a day, often unable to keep food or fluids down
• Nausea that's constant or nearly constant
• Weight loss, often 5% or more of your pre-pregnancy weight
• Dehydration: dark urine, peeing very little, dry mouth, dizziness when you stand, fast heartbeat
• Excess saliva, sometimes with spitting (yes, this is a real and common HG symptom)
• Exhaustion so deep you can't work or manage daily tasks
• Anxiety or depression because of how sick you are

What causes hyperemesis gravidarum?

Researchers don't fully understand it. Pregnancy hormones such as hCG are thought to be involved. Recent research has also linked HG to a hormone called GDF15, which is made by the placenta and acts on the brain's nausea center, and to how sensitive a person is to it. This work is still developing.

You may be more likely to have HG if you:

• Had it in a previous pregnancy
• Are pregnant with twins or more
• Have a family history of HG (a mother or sister who had it)
• Have a history of migraines or motion sickness

How is HG diagnosed?

There's no single test. Your provider looks at your symptoms, weight and signs of dehydration, and may order:

• Urine tests for ketones (a sign your body is breaking down fat because you aren't eating) and concentration
• Blood tests for electrolytes, kidney, liver and thyroid function
• An ultrasound to check for twins or a molar pregnancy, both of which can cause severe vomiting

They'll also rule out other causes, such as stomach infections, gallbladder disease, pancreatitis or migraine. Nausea that starts after 9 weeks is less typical of HG and needs a closer look.

The treatment ladder

Treatment steps up until your symptoms are under control. Many people skip straight to the middle rungs.

1. Diet and routine changes: small, frequent meals, avoiding triggers, and sometimes pausing iron-containing prenatal vitamins if they make nausea worse (your provider may suggest folic acid alone for now).
2. First-line medicine: vitamin B6 with or without doxylamine.
3. Prescription anti-nausea medicines, such as ondansetron, metoclopramide, promethazine or others. Sometimes more than one is combined.
4. IV fluids to treat dehydration and replace electrolytes, often in an urgent care setting, infusion area or hospital. Thiamine (vitamin B1) is given to people with prolonged vomiting to prevent a rare but serious brain complication called Wernicke encephalopathy.
5. Hospital care if you can't keep fluids down despite treatment.
6. Options for severe cases: corticosteroids (usually avoided before 10 weeks), or nutrition through a feeding tube or IV if weight loss continues.

Your care team picks medicines and doses based on your symptoms and how far along you are. Don't adjust doses on your own. Our guide to safe medications during pregnancy explains how providers weigh the choices.

What an IV fluid visit is usually like

You'll have an IV placed in your hand or arm, and a bag of fluid runs in over an hour or two, often with anti-nausea medicine and vitamins added. Many people feel noticeably better before the bag is finished. Bring a phone charger, a sweater and someone to get you home. If you need fluids repeatedly, ask your provider whether there's an outpatient option so you aren't spending hours in an ER each time.

Does HG affect the baby?

With treatment, most people with HG have healthy babies. Long-lasting, poorly controlled HG with significant weight loss has been linked to a higher chance of low birth weight and preterm birth. That's one of the main reasons to get treated early rather than wait it out.

HG and your mental health

HG is isolating and exhausting. Many people feel anxious, depressed, or guilty that they can't work, eat or care for their other kids. Some develop post-traumatic stress symptoms after a severe course. Tell your provider how you're feeling emotionally, not just physically; mental health support is part of treatment. Peer groups, such as those run by the Hyperemesis Education & Research (HER) Foundation, help many people feel less alone.

Getting through the day

Medical treatment comes first, but small things make the days more bearable:

• Keep fluids within reach and take tiny, frequent sips; ice chips or frozen fruit pops are often easier than drinking
• Eat whatever stays down, even if it isn't "healthy" right now
• Avoid smells that set you off, and ask others to cook
• After vomiting, rinse your mouth with water before brushing to protect your enamel
• Rest as much as you can and say yes to help with chores and childcare
• If you commute, keep a bag, mints and water with you, and know where the bathrooms are on your route

Your rights at work

The federal Pregnant Workers Fairness Act requires employers with 15 or more employees to provide reasonable accommodations for pregnancy-related conditions, and New York State law also requires employers to accommodate pregnancy-related conditions. That can mean remote days, a modified schedule or breaks. A note from your provider helps.

Planning another pregnancy after HG

HG often comes back. If you've had it before:

• See your provider before trying to conceive, if you can
• Ask about starting anti-nausea medicine at the first sign of symptoms, or even before
• Line up practical help at home for the first trimester

Getting care for HG in New York

Severe HG may need care from both your OB/GYN and a maternal-fetal medicine specialist, especially if you've been hospitalized or keep losing weight. Hospitals across NYC, Long Island and the Hudson Valley can provide IV hydration. If you're uninsured, NY Medicaid covers pregnant people with incomes up to 223% of the federal poverty level, and presumptive eligibility can cover care while your application is processed. Search the directory, or browse OB/GYNs in Queens and other boroughs.

When to call your provider or go to the ER

Call your provider the same day if you:

• Can't keep down any food or fluids for 24 hours
• Are peeing very little, or your urine is dark
• Have lost weight
• Feel dizzy or faint when you stand

Go to the emergency room if you:

• Vomit blood or material that looks like coffee grounds
• Have severe belly pain
• Feel confused, very weak, or have trouble walking or seeing clearly
• Faint, or have a racing heartbeat that won't settle
• Have thoughts of harming yourself

Frequently asked questions

Sources

• ACOG — Nausea and Vomiting of Pregnancy (Practice Bulletin 189)
• ACOG — Morning Sickness: Nausea and Vomiting of Pregnancy FAQ
• MedlinePlus — Hyperemesis Gravidarum
• NIH National Library of Medicine — Hyperemesis Gravidarum (StatPearls)

This article is for general education and is not medical advice. It does not replace an evaluation by a licensed clinician who knows your history. If you think you have a medical emergency, call 911.