'I'm feeling much better, thank you': Pregnant Duchess of Cambridge leaves hospital after being treated for severe morning sickness

Kate Middleton left the hospital carrying a bouquet of yellow flowers and looking relaxed, with her husband Prince William at her side.

The Duke and Duchess of Cambridge leaving the King Edward VII hospital in central London after her treatment for severe morning sickness (AFP/Getty)

The Duchess of Cambridge has been discharged from the King Edward VII Hospital, where she was receiving treatment for severe morning sickness.

The Duchess left the hospital carrying a bouquet of yellow flowers and looking relaxed, with her husband Prince William at her side.

She gave a brief smile to the waiting press and said "I'm feeling much better, thank you" before being driven away to her London home, Kensington Palace.

The royal couple will now spend time at the palace to allow for the Duchess, who is less than 12 weeks pregnant, to recuperate from the effects of the severe morning sickness.

She was admitted on Monday after developing the condition known as hyperemesis gravidarum, and was suffering from the effects of dehydration.

For medical staff to allow Kate to go home, her severe vomiting must be under control and they are likely to have given her anti-sickness medication.

Her discharge comes the day after it emerged that two Australian radio DJs impersonated the Queen and the Prince of Wales to dupe hospital staff into giving a condition update on the Duchess.

The 2Day FM presenters, Mel Greig and Michael Christian, apologised for their actions, as did their radio station.

But Christian has been promoting their stunt on Twitter telling followers in a tweet: "Still haven't heard the #RoyalPrank that has the world talking? Listen to it here..."

In a brief statement, St James's Palace said: "The Duchess of Cambridge has been discharged from the King Edward VII Hospital and will now head to Kensington Palace for a period of rest.

"Their Royal Highnesses would like to thank the staff at the hospital for the care and treatment the Duchess has received."