Heart disease is the number one killer in the United States. Most heart attacks are not that easy to recognize. They may start slowly with mild pain and discomfort.

Some warning signs of a heart attack include the following:

• Chest discomfort
• Discomfort in other areas of the upper body, such as back, neck, jaw, stomach or arms
• Shortness of breath
• Other signs, including nausea, lightheadedness or breaking into a cold sweat