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