Deteriorate= To diminish or impair in quality, character, or value: Example:Time and neglect had deteriorated the property. 1. To grow worse; degenerate: Example: The weather deteriorated overnight. His health had deteriorated while he was in prison. 2. To weaken or disintegrate; decay: Example:The nation's highways are deteriorating at a rapid pace. exacerbate = to make something which is already bad, even worse: Example: This personal attack will exacerbate the already tense relations between the two people. aggravate = to make worse 1 to make a bad situation worse: Example:Attempts to restrict parking in the city centre have further aggravated the problem of traffic congestion. 2 to make a disease worse: Example :The treatment will only aggravate the condition.

Hm... tricky to Explain... but there is a difference! Aggrevate is more... provoking something. Deteriorate is when something has its condition worsened. So being aggrevated - sort of like being provoked into a negative direction... being deteriorated - having something's condition change for the worse. One is more actively undergoing than the other. Deteriorating is generally more passive(and more gradual), while aggrevating usually is not. I COULD be wrong, but I think I'm correct,even if I don't explain it perfectly ^^;; EDIT: Oh, and exacerbate is more or less the same as aggravate

both words come from Latin deterior(ate) - to make worse, aggravate(aggravare) - to make more heavy (serious); aggravate an injury; a deteriorating situation; the deteriorating economy aggravates the unemployment situation