One expert says hyperemesis gravidarum is “a thousand times worse than morning sickness.” The ailment can cause serious and even life-threatening health issues.

Dr. Marlena Fejzo was just five weeks into her pregnancy when she was hospitalized with severe dehydration.

Her doctor sent her home with a bottle of pills and a picture of her healthy baby inside her womb.

But the next 10 weeks of her pregnancy were unbearable.

“I could not move without vomiting. I did not sit up, go to the bathroom, take a shower, brush my teeth, or leave my bed for 10 miserable weeks,” Fejzo told Healthline. “I had hypersalivation and had to use a machine like they have at the dentist’s office to suck off the excessive saliva. I was basically foaming at the mouth like a poisoned animal.”

Fejzo was suffering from a condition known as hyperemesis gravidarum (HG), a debilitating and in some cases life-threatening disease during pregnancy that causes unrelenting nausea and vomiting.

It’s the same condition currently affecting Kate Middleton, the duchess of Cambridge, in her third pregnancy.

Zofran, a medication used to prevent vomiting during chemotherapy, was pumped into Fejzo’s leg.

She eventually lost so much weight there wasn’t any fat left in her thigh to absorb the medicine, so her doctor switched to an IV in her arm.

The Zofran didn’t help and Fejzo became so weak from starvation she couldn’t talk and needed to use a buzzer to communicate.

“I hadn’t been able to keep any food down for 10 weeks and tried over 7 anti-nausea medications,” she said. “Eventually I was given nutrition through a tube, but it was too late. The baby died at 15 weeks. After that, I decided to devote my life to researching HG.”

Currently, there is no system in place to track the number of people with HG.

In addition, doctors fail to diagnose a significant number of women with the condition.

According to Fejzo, HG occurs in as many as 2 percent of pregnant women.

Nausea and morning sickness are often a normal part of early pregnancy for many women. But for women with HG, symptoms can be much worse.

Dr. Aimee Brecht-Dosser, an OB-GYN from Los Angeles who lost her first son at 18 weeks due to HG, says women should pay attention to their symptoms and not assume it’s only morning sickness.

“HG is a thousand times worse than morning sickness,” Brecht-Dosser told Healthline. “Women should seek care when the nausea affects their day-to-day function. If they are losing weight or are unable to keep things down, they should see their doctor right away.”

During Brecht-Dosser’s pregnancy, she felt pressured to soldier on and go about her day-to-day life despite her symptoms.

She cautions other women not to make the same choice.

“I told myself I was not sick, just pregnant. Meanwhile I was hooking myself up to an IV at night and disconnecting it in the morning to go to work. That was pretty stupid.”

HG contributes to 375,000 hospital admissions in the United States annually.

Getting medical assistance as soon as possible helps to prevent dangerous complications.

“If the mother loses more than 2 pounds in 1 week, is unable to drink for more than 24 hours, experiences relentless vomiting — some women report 50 times a day — vomits blood, has vision changes, difficulty walking, or loss of consciousness, she should seek care immediately,” Kimber MacGibbon, RN, co-founder of the Hyperemesis Education and Research Foundation, told Healthline.

MacGibbon experienced HG in both of her pregnancies. She now has two healthy children but says her health never returned to normal after her pregnancies.

Despite this, in many ways, she is one of the lucky ones.

“In our support groups, we generally will have at least one or two mothers die due to complications of HG every year,” she said. “Sometimes it’s due to a rupture of their esophagus, complications of malnutrition such as neurological damage from vitamin B-1 or thiamin deficiency, or damage to their kidneys from dehydration. Beyond the mothers we lose, there is a 1 in 3 fetal loss rate.”

The consequences of HG extend beyond the physical and can have a significant impact on relationships.

“So many families are devastated financially and emotionally by HG. About 1 in 4 women terminate at least one pregnancy, which leads to tremendous grief that may last a very long time. So many women have symptoms of trauma and have to change their future pregnancy plans as a result of HG,” MacGibbon said.

Brecht-Dosser was one of the women who had to make a choice after losing a baby to HG.

“I made a difficult decision to get pregnant again because I knew I wanted to be a mother. During my second pregnancy I was so sick we were concerned I would not survive even with the best medical care,” she said. “It was terrifying. My son is an only child because I could not risk my life again when he needed me. Even though I learned about HG in my training as an OB-GYN, I did not understand it before I suffered with it myself.”

Lack of awareness around the disease and the belief in myths on the part of both medical providers and lay people can make a difficult situation much worse for women experiencing HG.

Some believe that because HG is rare, it’s unlikely to occur again. In reality, the rate of recurrence is approximately 80 percent.

Some believe HG will go away after the first trimester. Although this may be true of morning sickness, HG can last into the second trimester or for the entire pregnancy.

Some believe HG is a sign of a healthy baby. However, in women with severe symptoms there is a higher risk of miscarriage and long-term neurodevelopmental effects.

It’s this lack of understanding that has motivated Fejzo to dedicate her life to researching HG.

“Some people will say ‘Oh, I had that, but I’m just a really strong person, so I just powered through it.’ This is infuriating to women with HG,” Fejzo said. “Women in my study have reported detached retinas, esophageal tears, rib fractures, and blown eardrums from the violent vomiting. It is much more severe than morning sickness. It can be a form of prolonged starvation, malnutrition, and stress during pregnancy that can have a lasting impact.”