After the Duchess of Cambridge Kate Middleton suffered a public bout of extreme morning sickness, people have been wondering what exactly is the disease that struck the newly pregnant royal.
URMC obstetrician Loralei Thornburg says about 20,000 pregnant women suffer from an extreme form of morning sickness.
While nearly every pregnant woman suffers from some form of nausea, there are signs that show if a woman is suffering from the more serious type and should see a doctor.
"Hyperemisis is distinguished because you have to have both weight loss, dehydration and evidence of that in your urine and in your electrolytes to suggest that you have more than average nausea and vomiting in your pregnancy," said Obstetrician Loralei Thornburg.
"Personally I would ask their health care provider because what I thought was working was not working," said Brooklyn Rhines, patient. "I thought not eating would help, but not eating would make it worse."
Women suffering from extreme morning sickness are encouraged to eat small, bland meals frequently.