Kelly Osbourne may have epilepsy.
The 'Fashion Police' host - who was rushed to Cedars Sinai hospital in Los Angeles after suffering a 30 second seizure on the set of the E! series - has been warned by doctors that the dramatic health scare could be much more serious than they initially suspected.
A source told gossip website TMZ.com that Kelly's medical team are running tests and she will remain in hospital for at least a few more days while they try to determine what caused the sudden seizure.
The insider said she is currently on anti-seizure medication and doctors are closely monitoring her as they believe the seizure was extremely serious.
The 28-year-old star took to her Twitter account to show her appreciation for all the "beautiful well wishes" she received following the frightening incident.