Definitions of complication:

• noun:   the act or process of complicating
• noun:   a development that complicates a situation
• noun:   a situation or condition that is complex or confused

  Example: "Her coming was a serious complication"

• noun:   any disease or disorder that occurs during the course of (or because of) another disease

  Example: "Bed sores are a common complication in cases of paralysis"

• noun:   puzzling complexity