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. May occur with or without chest discomfort.
• Other signs: These may include breaking out in a cold sweat, nausea or lightheadedness

If you or someone you're with has chest discomfort, especially with one or more of the other signs, don't wait longer than a few minutes (no more than 5) before calling for help. Call 9-1-1... Get to a hospital right away.

Stroke Warning Signs
The American Stroke Association says these are the warning signs of stroke:

• 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
  

If you or someone with you has one or more of these signs, don't delay! 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 can reduce long-term disability for the most common type of stroke.

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 Automated External Defibrillator (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 Automated External Defibrillator (AED) (if one is available) before you begin CPR.

Source: American Heart Association