"Emotional stability" refers to a person's ability to remain calm or even keel when faced with pressure or stress. Someone who is emotionally unstable is more volatile, which means the person faces an increased risk of reacting with violent or harmful behaviors when provoked.
People who recognize stress triggers and build healthy coping skills tend to maintain emotional stability better than those who don't. Irrational thinking, impulsiveness and certain medications contribute to increased levels or emotional instability. Methods used to moderate emotional responses include religious practices, meditation, exercise, proper nutrition and healthy sleeping habits. A lack of emotional stability means someone feels more emotional highs and emotional lows.