Prince William reveals Kate Middleton's trick to ease morning sickness

Prince William has revealed Kate Middleton is trying a number of natural remedies to ease her severe morning sickness.

The Duchess, who is pregnant with her third child, suffers from Hyperemesis gravidarum, which causes severe nausea, dehydration and low blood pressure.

And experts say the illness worsens with every subsequent pregnancy.

During a recent engagement celebrating the Metropolitan and City Police Orphans Fund, Prince William spoke with 98-year-old Iris Orrell about his wife's condition.

Orrell - a mother to three sons - revealed that she also suffered from Hyperemesis gravidarum and suggested the Duchess try "dry biscuits".

The 35-year-old royal explained his wife had been trying ginger biscuits, "but there's not much ginger can do to stop that - we've done all that."

Instead, Kate prefers lavender shortbread cookies, a "traditional" remedy that was apparently suggested to her by Camilla.