Kate Middleton And Prince William
Britain's Prince William and his wife Catherine, Duchess of Cambridge stand amid the Tower of London's 'Blood Swept Lands and Seas of Red' poppy installation to commemorate the 100th anniversary of the outbreak of World War One (WW1), in London August 5, 2014. Reuters/Luke MacGregor

After months of speculation, royal officials finally confirmed Kate Middleton's second pregnancy after cancelling her scheduled travel to Oxford with Prince William. The Duchess is currently treated by doctors due to an acute morning sickness or also known as hyperemesis gravidarum.

Clarence House was forced to announce the pregnancy news when Kate was admitted to the hospital after suffering the same illness from her first pregnancy in 2012. Currently receiving treatment in Kensington Palace, the 32-year-old brunette is thrilled to have another baby despite having a tricky few days of her pregnancy.

Here are the six things to know about hyperemesis gravidarum, pregnant Kate Middleton's condition.

1. Also means excessive vomiting in pregnancy, HG is not a common condition for pregnant women as it only affects three per cent of soon-to-be-moms. Expectant mothers who are suffering from this illness will have a hard time keeping anything down, even swallowing their own saliva would be a challenge.

2. This condition occurs four to 10 weeks of pregnancy. The symptoms include weight loss, dehydration, headaches, lethargy, low blood pressure and ketosis, a build-up of toxins in the blood as well as in urine.

3. Although there are various hypothesis about the causes of HG, there is not enough proof why some women experience this severe form of nausea and vomiting. There are some early treatments that could lessen the symptoms of the illness and prevent it from developing. If treated accordingly, it's very unlikely that the baby will be harmed. But if the mother suffered weight loss during pregnancy then there is a chance that the baby is smaller than average but will not be affected by the illness.

4. Expecting mothers with HG will be exhausted, depressed and will not be able to experience the pregnancy bliss. Women become withdrawn and they often feel isolated that could affect their relationship with their partner.

5. Women who are at risk of having HG include mothers who are expecting twins and triplets, have pre-existing liver disease, prone to travel sickness and those who suffered HG in their past pregnancy.

6. Other celebrities who suffered from the condition include former Atomic Kitten singer Jenny Frost and property expert Kirstie Allsopp.