Is there a single word for a messy person?

It is with great regret I must tell you that there is not just one word for someone who is messy. This is because of the many reactions to the messiness that find voice from the family and friends and others that must deal with such people.

Slob may seem to have the connotation of laziness but I believe that it is actually the notion that they simply do not mind the mess or the condition the live in. It just does not bother them and so they let things lie.

Other words that come to mind are Careless (leaves the glass in the sink) Thoughtless (does not realize others care and will have to clean up) but also Preoccupied (they are focused on something else. Soon you get to Unhealthy or Diseased and other words that carry far more weight than needed.