Tests at a San Francisco hospital have shown that Sharon Stone has suffered bleeding on the surface of her brain.
The actress will have to undergo another angiogram to determine whether or not she had an aneurysm.
Doctors discovered that Stone suffered a subarachnoid haemorrhage, or bleeding into the space between the brain and the middle membrane covering the brain, her publicist Cindi Berger said.
The Oscar-nominated actress has been in hospital for several days suffering from severe headache.
