Woman Experiences Duchess Kate's Severe Morning Sickness

INSIDE EDITION speaks to a woman who experienced the severe morning sickness condition that landed Duchess Kate in the hospital.

A tense Prince William arrived at the hospital to spend another day at Kate's bedside. But he was smiling in relief when he left six hours later. He and Kate just released a statement saying Kate is "continuing to feel better." They also said they were immensely grateful for the good wishes they have received."

We're learning more about the rare form of acute morning sickness afflicting Kate. It's left her debilitated in bed, hooked up to an IV to restore fluids and nutrients. She's taking medication to ease her extreme nausea.

CBS News correspondent Mark Phillips is camped outside King Edward VII Hospital in London and reports, "There is a little bit of concern about Kate's condition. She, of course, has come into the hospital here in Central London suffering from what they're calling acute morning sickness, which, in her case, seems to mean all day sickness. Severe vomiting, the inability to keep anything down."

Obstetrician Lisa Masterson of TV's The Doctors says the condition known as Hyperemesis Gravidarum can leave an expectant mother wasted away.

Masterson told INSIDE EDITION, "It's absolutely miserable. It's just the worst thing. You're doing this incredible thing by having a baby. It should be the most happy, beautiful time in your life, and you are completely miserable."

Mimi Chang knows what Kate is going through. The Los Angeles mom says she has felt so nauseous it's often impossible to eat or drink. Some days, she can barely drag herself out of bed. And it lasted for six months.

Chang said, "If you just imagine stomach flu, food poisoning, but it's 24/7. There's just no reliefe from the nausea. I really knew something was wrong when I weighed myself and I realized that I had lost 15 pounds."

Playmate Holly Madison from Dancing with the Stars is pregnant. She just tweeted a photo of an I.V. in her arm, tweeting: "Almost 7 months and morning sickness took hold! Glad to be otherwise ok, tho."

Despite her terrible discomfort, Kate and William are said to be "reassured" by their doctors that Kate and the baby will be ok.

The pregnancy has sparked mass excitement around the world. Headlines blared the news of Kate's sickly condition and rumors of twins.

Now, everyone's wondering. When is Kate's due date?  The palace will only say that she's in her first trimester. That means the blessed event could happen between May and July.

There's growing speculation that the royal heir was conceived during Will and Kate's trip to Southeast Asia in September. There could have been no more romantic setting than the bungalow where they stayed in the Solomon Islands, or the presidential suite at a spectacular hotel in Singapore.