exacerbate

verb. make something bad even worse

"the forest fire was exacerbated by the lack of rain"
"the construction of the bridge will result in intense deforestation and will exacerbate, rather than alleviate, İstanbul's traffic crisis"
"Continually taunting your coworker about the error he made will only exacerbate his anger, and won't help him learn from his mistake."

http://www.vocabulary.com/dictionary/exacerbate