For a person suffering from severe anxiety is there a risk for heart/brain attack? my sister is so anxious she fainted today after she saw a car wreck

Anxiety: As per your information, you are 11 year old. I understand your concerns about your sister. Tell your concerns to older people in your home, and in their presence, tell your sister that you love her. Anxiety may cause rapid heart rate, increased blood pressure and fainting. There is no risk of brain attack. As a family, see Psychiatrist for counseling. Your sister can be helped with medication