Some heart attacks are sudden and intense — the “movie heart attack,” where no one doubts what's happening. But most heart attacks start slowly, with mild pain or discomfort. Often people affected aren't sure what's wrong and wait too long before getting help.

Here are signs that can mean a heart attack is happening:

• Chest discomfort. Most heart attacks involve discomfort in the center of the chest that lasts more than a few minutes, or that goes away and comes back. It can feel like uncomfortable pressure, squeezing, fullness or pain.
  
• Discomfort in other areas of the upper body. Symptoms can include pain or discomfort in one or both arms, the back, neck, jaw or stomach.
  
• Shortness of breath with or without chest discomfort.
  
• Other signs may include breaking out in a cold sweat, nausea or lightheadedness
  

As with men, women's most common heart attack symptom is chest pain or discomfort. But women are somewhat more likely than men to experience some of the other common symptoms, particularly shortness of breath, nausea/vomiting, and back or jaw pain.

Learn the signs, but remember this: Even if you're not sure it's a heart attack, have it checked out (tell a doctor about your symptoms). Minutes matter! Fast action can save lives — maybe your own. Don’t wait more than five minutes to call 9-1-1.

Cardiac arrest strikes immediately and without warning.

Here are the signs:

• Sudden loss of responsiveness (no response to tapping on shoulders).
  
• No normal breathing (the victim does not take a normal breath when you tilt the head up and check for at least five seconds).
  

If these signs of cardiac arrest are present, tell someone to call 9-1-1 and get an AED (if one is available) and you begin CPR immediately.

If you are alone with an adult who has these signs of cardiac arrest, call 9-1-1 and get an AED (if one is available) before you begin CPR.

Use an AED as soon as it arrives.

If you or someone with you has one or more of these signs, don't delay!

• Sudden numbness or weakness of the face, arm or leg, especially on one side of the body
• Sudden confusion, trouble speaking or understanding
• Sudden trouble seeing in one or both eyes
• Sudden trouble walking, dizziness, loss of balance or coordination
• Sudden, severe headache with no known cause

Immediately call 9-1-1 or the emergency medical services (EMS) number so an ambulance (ideally with advanced life support) can be sent for you. Also, check the time so you'll know when the first symptoms appeared. It's very important to take immediate action. If given within three hours of the start of symptoms, a clot-busting drug called tissue plasminogen activator (tPA) can reduce long-term disability for the most common type of stroke. tPA is the only FDA-approved medication for the treatment of stroke within three hours of stroke symptom onset. A TIA or transient ischemic attack is a “warning stroke” or “mini-stroke” that produces stroke-like symptoms but no lasting damage. Recognizing and treating TIAs can reduce your risk of a major stroke. The usual TIA symptoms are the same as those of stroke, only temporary. The short duration of these symptoms and lack of permanent brain injury is the main difference between TIA and stroke.

© 2009 American Heart Association, Inc