Tanzian flu was a type of medical condition that caused severe increase of respiration, dilation of pupils, and elevated blood flow to the ears, resulting in an orange coloration.

In 2372, The Doctor believed Tom Paris was suffering from the Tanzian flu until he realized that the timing of Paris' symptoms corresponded with Kes entering the room. This led him to diagnose Paris as being in love with the Ocampa woman instead. (VOY: "Parturition")