most helpful answer you're right: since the duchess of cambridge was admitted to the hospital with hyperemesis gravidarum (hg) everyone's been asking what it really is. hyperemesis gravidarum literally means excessive (hyper) vomiting (emesis) due to pregnancy (gravidarum). many women get morning sickness -- nausea and/or vomiting -- in the early stages of pregnancy so a lot of people are asking why kate middleton had to be hospitalized for what amounts to a bad case of morning sickness. hyperemesis gravidarum however is a serious medical condition. a woman with hg may lose as much as 5% of her total body weight due to fluid loss. this can not only put the baby at risk but can cause electrolyte imbalances in the mother that can lead to a heart attack. fortunately hg is a very rare condition. most women never have morning sickness that reaches the level of hg. the duchess of cambridge was simply unlucky in this respect. hope that explains things for you.
what is hyperemesis gravidarum and is it similar or different to anything. basically having a hard time founding any useful info regarding all of this. besides what i have found regarding morning sickness nausea vomiting. especially in light that catherine (kate middleton) duchess of cambridge is currently suffering from it.