Dr. Michael Smith: You’re lying in bed, and you get sudden chest pain. Is it harmless, or are you having a heart attack? If you don’t know what a heart attack feels like, here are the top signs. One, Chest Pain. Not a surprise. Pay close attention to discomfort on the left side of the chest. It can feel like tightness or squeezing. This feeling will last more than a few minutes, but it can come and go. Two, Shortness of Breath. This is especially common in women, even moreso than chest pain. So if you’re barely moving, but are breathing like you’ve just ran a marathon, take note. Three, Upper Body Pain. If the pain isn’t limited to your chest, that’s a signal. Men commonly feel some discomfort in one or both arms. A lot of times women will feel it in their back or jaw. Four, Dizziness. You might feel dizzy, nauseous, and break out in a cold sweat if you’re having a heart attack. If you have these symptoms, don’t waste time, and call 9-1-1. When in doubt, check it out. For WebMD, I’m Dr. Michael Smith.