​1. Guess a random disease, which could be anything, and then the categories that match up(mostly) correct will light up green and reveal themselves

2.In every game mode there is at least 1 hidden category, but for hard mode there is an extra 2 pieces hidden and in impossible an extra.

3. Hidden categories mean that even though your guessed disease matches, it WILL NOT highlight green and reveal itself.

4.Images are only available on easy mode.