This article lists behaviors and issues that can harm a relationship and lead to its demise. They include neediness, insecurity, lack of relationship knowledge, lack of self-control, money, controlling behavior, arguments, difference in life goals, difference in core values, being at different points in life and substance abuse. The article suggests that by being aware of these potential relationship killers, and understanding how they may have contributed to your relationship ending, you can make a conscious effort to address and overcome them in future relationships.