Catnip is most commonly used to treat nervousness and anxiety, along with other symptoms these conditions can cause, such as indigestion and insomnia. It may be used to treat conditions or symptoms related to gastrointestinal upset, including indigestion, cramping, and gas. It can act as a diuretic, increasing urination and thus decreasing water retention. This could help in the treatment of a number of different conditions. Catnip has historically been used to treat issues like arthritis, coughs, hives, fevers, and viruses. And of course you can use it to make your cats go crazy and your dog calm down!