Why Do Humans Get Sick?

Humans get sick when something inside or outside of their body causes them to feel unwell. It's like getting a bad cold, a tiny germ sneaks into your nose and starts making you cough and sniffle. Sometimes it's even bigger problems, like when bacteria or viruses attack the whole body. Just like how a toy breaks when someone kicks it too hard, our bodies get sick when something causes them to feel weak.