Severe morning sickness for the duchess

The duchess of Cambridge has been admitted to King Edward VII Hospital suffering from severe morning sickness.

Hyperemesis gravidarum is a rare condition which causes severe vomiting during pregnancy. The severity of the vomiting can cause dehydration, weight loss, and a build-up of toxins in the blood or urine called ketosis.

It affects 3.5 per 1,000 pregnant women.