The article says: "Getting angry [...] is damaging to our hearts, brains and gastrointestinal systems [...] it’s a normal emotion that everyone feels [...] But

The article says: "Getting angry [...] is damaging to our hearts, brains and gastrointestinal systems [...] it’s a normal emotion that everyone feels [...] But getting mad too often or for too long can cause problems." Like it says on Wikipedia, by the Buddhist teaching, they are "poisons", and this also means that it is "poison". I agree with what you say, there are skillful and unskillful ways to relate to all things that arise.