Antecedents are the predisposing factors. Consider your family history that may predispose you to illness; genetics; mom and dad’s health history and anything of note in your family or ancestry prior to that. Consider how you were born, your age and gender as well.
Triggers are anything that initiated or provoked the emergence of symptoms. Consider life history and pivotal moments along the way that seemed to tip the scales into a state of significant illness or signs and symptoms. Think about travel or food poisoning or a particular infection or a major occurrence in life.
Mediators may be more challenging to nail down. The mediators are the factors that seem to exacerbate or ameliorate symptoms. These are the things that contribute to the manifestation of illness– stress, eating certain foods (like gluten or sugar), being in certain situations that are taxing are all of note.