Mayo Clinic Health Manager
Get free personalized health guidance for you and your family.
Get Started
About our e-newsletters
- Free e-newsletters
- Mayo Clinic expertise
- We do not share your e-mail address
Housecall, our weekly general-interest e-newsletter, keeps you up to date on a wide variety of health topics with timely, reliable, practical information, recipes, blogs, questions and answers with Mayo Clinic experts and more. Our biweekly topic-specific e-newsletters also include blogs, questions and answers with Mayo Clinic experts, and other useful information that will help you manage your health.
Housecall Archives
Mayo Clinic Housecall
Stay up to date on the latest health information.
What you get
- Free weekly e-newsletter
- Mayo Clinic expertise
- Recipes, tools and other helpful information
- We do not share your e-mail address
Symptoms
By Mayo Clinic staffSudden cardiac arrest symptoms are sudden and drastic:
- Sudden collapse
- No pulse
- No breathing
- Loss of consciousness
Sometimes, other signs and symptoms precede sudden cardiac arrest. These may include fatigue, fainting, blackouts, dizziness, chest pain, shortness of breath, palpitations or vomiting. But sudden cardiac arrest often occurs with no warning.
When to see a doctor
If you have frequent episodes of chest pain or discomfort, heart palpitations, irregular or rapid heartbeats, unexplained wheezing or shortness of breath, fainting or near fainting, or you're feeling lightheaded or dizzy, see your doctor promptly. If these symptoms are ongoing, you should call 911 or emergency medical help.
When the heart stops, the absence of oxygenated blood can cause brain damage in only a few minutes. Death will occur within eight to 10 minutes. Time is critical when you're helping an unconscious person who isn't breathing. Take immediate action:
- Call 911, or the emergency number in your area, if you encounter someone who has collapsed or is found unresponsive. If the unconscious person is a child and you're alone, administer CPR or chest compressions only for two minutes before calling 911 or emergency medical help or before using a portable defibrillator.
- Administer CPR. Quickly check the unconscious person's breathing. If he or she isn't breathing normally, begin CPR. If you don't know CPR, just push hard and fast on the person's chest — about two compressions per second or 100 per minute. Allow the chest to rise completely between compressions. Don't worry about breathing into the person's mouth. Keep doing this until a portable defibrillator is available or emergency personnel arrive.
- Use a portable defibrillator, if one is available. If you're not trained to use a portable defibrillator, a 911 or emergency medical help operator may be able to guide you in its use. Deliver one shock if advised by the device, then immediately begin CPR starting with chest compressions, or give chest compressions only, for about two minutes. Using the defibrillator, check the person's heart rhythm. If necessary, the defibrillator will administer a shock. Repeat this cycle until the person recovers consciousness or emergency personnel take over.
Portable automatic external defibrillators (AEDs) are available in an increasing number of places, including airports, casinos and shopping malls. You can also purchase them for your home. AEDs come with built-in instructions for their use. They're programmed to allow a shock only when appropriate.
