The Basic Instinct actress was attending the Fendi catwalk show at Milan Fashion Week on Friday (September 21) when the migraine pain became unbearable.
According to WENN, she was rushed to a Milan hospital where she underwent a series of medical tests.
She was in better health by Saturday (September 22), when she was able to attend an AIDS charity event as a guest of honour.
Stone told reporters: "I feel fine and I'm good and I've got a clean bill of health and I'm happy to be here."
The 54-year-old, who recently joined the mother-daughter film Mother's Day, suffered a brain aneurysm in 2001.