The American College of Emergency Physicians states that these warning signs suggest a true medical emergency:

• Trouble breathing or shortness of breath
• Pressure or pain in the chest or upper abdomen
• Fainting, sudden dizziness, or weakness
• Changes in vision or mental status
• Severe abdominal pain
• Uncontrolled bleeding
• Severe or persistent vomiting or diarrhea
• Coughing or throwing up blood

If you or someone else is having any of these symptoms, call 911 immediately.