exacerbate =
to increase the severity, bitterness, or violence of (disease, ill feeling, etc.); aggravate, to embitter the feelings of (a person); irritate;
aggravate =
to make worse or more severe; intensify, as anything evil, disorderly, or troublesome: to aggravate a grievance; to aggravate an illness.
to annoy; irritate; exasperate: His questions aggravate her. to cause to become irritated or inflamed: The child's constant scratching aggravated the rash.
deteriorate =
to make or become worse or inferior in character, quality, value, to disintegrate or wear away.