Hyperemesis gravidarum causes nausea and vomiting so severe, it forced the comedian to cancel a Texas stop on her tour.

Pregnant Amy Schumer has been hospitalized–but she and the baby are fine.

The actress and comedian apologized to fans on Instagram for having to cancel a Texas tour stop due to a severe form of morning sickness called hyperemesis gravidarum, which causes debilitating nausea and vomiting.

"I have hyperemesis and it blows. Very lucky to be pregnant but this is some bullshit!" Schumer wrote in her post.

Schumer's in royal company, battling hyperemesis gravidarum: Kate Middleton suffered from the condition during all three of her pregnancies. Like Schumer, Middleton's symptoms forced her to cancel public events.

So what might the next few months look like for Schumer, or any other pregnant women suffering from hyperemesis gravidarum? To find out, Health spoke with Richard Davis, MD, interim division director of maternal-fetal medicine at the University of Alabama at Birmingham. Dr. Davis is not involved in Schumer's care–nor did he treat Middleton–but he has treated other women with the same diagnosis.

Dr. Davis says hyperemesis gravidarum is different from regular morning sickness in that it is extremely hard for women to keep down any foods or liquids without vomiting. “Women can get dehydrated, they can lose significant amounts of weight, and they can obviously feel very weak,” he says. “It can become a dangerous cycle because the esophagus gets irritated from vomiting, which can cause reflex and contribute to the nausea, which then causes more vomiting.”

That’s why it’s so important for women with hyperemesis gravidarum to seek medical attention, Dr. Davis adds. Some women only need a few days of intravenous fluids to hydrate them and help the worst of their symptoms pass, while others need medications to calm their stomach and suppress nausea. In severe cases that have gone undiagnosed or untreated, women may also have vitamin deficiencies or other complications that need to be addressed.

The Duchess’s hyperemesis was bad enough during her first pregnancy with Prince George that she was hospitalized for four days in the “very early stages” of her pregnancy. For her second pregnancy, she was reportedly cared for at home, but she missed several high-profile appearances during her first trimester, including a trip to Malta and the Invictus Games for wounded servicemen and women.

Middleton also spent part of her first trimester at her parents’ home when she was carrying second-born Princess Charlotte. At that time, a family friend told People that Middleton was “not well at all, the poor thing.” Still, the fact that the Duchess was able to stay with her parents, who live about 50 miles from her main doctors, likely meant that her symptoms were being kept under control.

Middleton stayed out of the public spotlight during her pregnancy with Prince George until about the 13-week mark, and followed a similar pattern while pregnant with Princess Charlotte. In the later months of both pregnancies, she kept up a regular schedule of high-profile events and made plenty of headlines about her chic maternity (or, more accurately, non-maternity) style.

That makes sense, says Dr. Davis, since many women with hyperemesis gravidarum start to feel better around the 12- to 14-week mark. “They may still have some nausea or vomiting,” he says, “but most can keep it under control with strategies like small, frequent meals or natural remedies like ginger.”

That’s not true for everyone, however; some women experience serious symptoms throughout their entire pregnancies. And it's possible Schumer is one of them. "Everyone who says the 2nd trimester is better is not telling the full story. I’ve been even more ill this trimester," she wrote on Instagram.

There’s no way to prevent hyperemesis gravidarum from occurring and nothing a woman can do differently a second or third time around, but it can help if she and her doctors know what to expect, says Dr. Davis, and are prepared with preventive medicine and preemptive scheduling strategies.

“It can be challenging for women to keep up with work or their daily lives,” he says. “You have nausea, you may still be vomiting, and you just feel really lousy, so going out in public and keeping appointments can be hard, especially when food is involved.” (Just like with regular morning sickness, he explains, the smells and sights of certain foods can be potent triggers.)

At the same time, he says, women with hyperemesis gravidarum need to listen to their bodies and eat whenever—and whatever—they feel the urge to eat. “Even if it’s something very surprising, like if a woman says she wants a cheeseburger and French fries,” he says. “Chances are if she’s craving it, she’s going to be able to keep it down.”

Hyperemesis gravidarum can be physically and emotionally devastating, and in severe (and very rare) cases, it can cause long-term health issues for both mom and baby. But if a woman receives proper care and is able to manage her symptoms, she can recover fully and go on to have a perfectly healthy newborn.

Just look at Middleton’s two previous deliveries: Insiders told People that the Princess Charlotte’s birth went “extremely well,” and Middleton wowed her fans by appearing in public, looking radiant of course, shortly after giving birth to both George in 2013 and Charlotte in 2015.

Schumer at least seems in good spirits, praising the doctors and nurses taking care of her in her Instagram post, before promising she'll be back in the spotlight soon. "Texas I am really really sorry and I’ll be out there as soon as I’m better."

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