If you are sharing in a living situation with someone who you've found to be kind of a slob, i.e. not doing any cleaning nor taking care of personal hygiene, and it poses a health risk to both of you, how would you go about telling that person to cleanup? How can you tell another person that they are a health hazard without offending them but still make them understand?

Well, you could always cue up that song, "Hit The Road Jack" and see if that prompts any discussion.

Seriously though, you might have to take the risk of being offensive to that person, since they do not have clue one about what they are doing to themselves and to anyone else. Has this persons always been this way? Do you think there is some underlying emotional component to their behavior? As in depression?

If that were me facing this, I would tell the other person that I needed to talk to them about something that I am very concerned about. Then launch into what is going on. It is not something to dance around, as the point may become obscure if hidden too much. Maybe starting to talk about what is going on will lead to why this is going on. Who knows what the other person is holding onto - perhaps something he or she feels overwhelmed and powerless about. It is just a thought.

Hope all goes well. If, after this person has been in discussion about hygiene and still does not see what is going on or does not see personal habits as offensive, then call in medical support or someone who the other person would listen to.