Egosyntonic means that something is in agreement with a person's self-image or values. For example, if a person likes to play soccer, it is egosyntonic for them to spend their free time practicing and playing matches.
Egodystonic means that something goes against a person’s self-image or values. For example, if a person likes to play soccer, it would be egodystonic for them to no longer have any interest in playing.