 When we use debt to buy things, ultimately lose their value. It's bad debt. An example is buying groceries with a credit card. If the credit card balance is not paid in full, then you're left owing money on products you've already been consumed. Debt used to spend beyond your means is always bad debt. The worst use of a credit card is to purchase something you otherwise can't afford to purchase with cash. That is how people get into trouble with debt.