School shootings are a national crisis. Now, a mom reveals her secret fear: Could her son be the next mass murderer? She speaks out before the next tragedy strikes. Plus, the at-home test to diagnose a sluggish thyroid and the new public health threat affecting millions.

Dr. Oz goes where he's never gone before. He's letting you eat fast-food and it's not what you expect. Learn which fast food meals you can eat under 500 calories while still enjoying the food you love.

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