What her many fans may not know is that all that time—dating back to the early 90s—Stone was experiencing strange symptoms that she would later link to the near-fatal stroke she experienced in 2001. Read on to find out which symptom in particular Stone now wishes she’d taken more seriously, and why she’s urging others to call 911 if it happens to them. READ THIS NEXT: Maria Menounos Says This Was the First Symptom of Her Brain Tumor. “I was clearly having some mini seizures when I was doing Basic Instinct,” Stone told the New Yorker in 2021. “I used to tell people I was having them, and nobody would believe me.” Stone even said that people on the set of Basic Instinct thought she was on drugs. “And I kept saying, ‘I’m not taking drugs, and I don’t know why this happens to me,” she remembered. “So when this [stroke] happened, there was a little bit of ‘Ohhh.’” Stone may not have realized it at the time, but family history is considered a risk factor for stroke. “If your parent, grandparent, sister, or brother has had a stroke—especially before reaching age 65—you may be at greater risk,” warns the American Stroke Association. “Sometimes strokes are caused by genetic disorders… which can block blood flow in the brain.” In 2019, Stone spoke to Variety about her family history of stroke. “My mother had a stroke. My grandmother had a stroke. I had a massive stroke—and a nine-day brain bleed,” she said. “I think about it scientifically,” Sharon Stone said to the New Yorker of her 2001 stroke. “I bled so much into my subarachnoid space that my brain was literally shoved into the front of my face. The right side of my face fell from the pressure.“ae0fcc31ae342fd3a1346ebb1f342fcb What actually happens when a stroke occurs? Our brains need oxygen to function. The arteries deliver oxygen—in the form of blood—to our brains. According to the Centers for Disease Control and Prevention (CDC), a stroke occurs “when something blocks blood supply to part of the brain or when a blood vessel in the brain bursts. In either case, parts of the brain become damaged or die,” they warn. “A stroke can cause lasting brain damage, long-term disability, or even death.” After her stroke, Stone experienced financial and marital woes, as well as other symptoms, she told the New Yorker: “I lost 18 percent of my body mass,” she recalled. “Food I really liked I became allergic to, medicines I became allergic to, all kinds of things changed.” For more health news sent directly to your inbox, sign up for our daily newsletter. Recognizing stroke symptoms as soon as possible is crucial. “The stroke treatments that work best are available only if the stroke is recognized and diagnosed within three hours of the first symptoms,” the CDC advises. “Stroke patients may not be eligible for these if they don’t arrive at the hospital in time.” According to WebMD, common stroke symptoms include weakness or numbness on one side of your face or in one arm or leg, sudden loss of balance, dizziness or sudden falls, brief fainting spells, and sudden, dimmed vision in one eye. “‘Sudden’ and ‘severe’ are key words,” Doojin Kim, MD, said about the onset of stroke in HealthDay News. “But if in doubt, do not take chances.” Another symptom of stroke—and one that Stone wishes she had sought medical attention for—is an intense headache. When Stone experienced this, she didn’t call 911. But she now warns others with similar symptoms to seek medical attention. “If you have a really bad headache, you need to go to the hospital,” she told Variety. Speaking with Brain & Life, Stone described experiencing “a lightning bolt” of pain so severe that it knocked her to the floor, where she blacked out. After regaining consciousness, she said she felt confused and had a bad headache. Eventually, Stone went to the hospital. “When I came to, the doctor was leaning over me,” she explained to Harper’s Bazaar. “I said, ‘Am I dying?’ And he said, ‘You’re bleeding into your brain.’” The doctor was describing a hemorrhagic stroke, which occurs when a blood vessel bursts and causes bleeding in the brain. “I had a one percent chance of living by the time I got surgery—and they wouldn’t know for a month if I would live,” Stone told Variety. According to the CDC, intracerebral hemorrhage “accounts for 10-15 percent of all strokes and carries very high morbidity and mortality rates.” But the time, Stone didn’t know that. “No one told me,” she said to Variety. “I read it in a magazine.” If you have symptoms of a stroke, including a sudden severe headache, seek medical attention immediately. READ THIS NEXT: You’re Half as Likely to Have a Stroke If You Do This Once a Week, Study Says.