Unless you're an extraordinarily confident person, the knowledge that a friend is hanging out with another without issuing you an invitation can be a ticket for a day of insecurity and jealousy. If you recognize your feelings, you're already a step ahead of the person who would cross the offending friend off the invite list for her wedding shower. It's perfectly normal for people to seek out a variety of relationships, and learning how to deal with your feelings of insecurity within your friendships will help you foster even healthier connections.

Realize that you can't be all things to all people. Our individual friendships meet different emotional needs. While one friend may be the perfect person to talk with about the meaning of life at 2 in the morning, another may be a better person to call when you need cheering up after an argument with your partner. Recognize that your friends need a variety of needs met as well. If your best buddy meets up with another woman for coffee, kick jealousy to the curb by remembering that your eyes tend to glaze over when your friend begins to talk about her ongoing struggle with her weight and perhaps another friend can offer more encouragement.

It's hard to be jealous of your pal going shopping with another friend if you're busy hanging out at the pool drinking mimosas with someone else. If you feel lonely and insecure when friends do things in which you are not included, develop your life to the point where you are grateful to have a break to pursue your own interests with different people. Just as you can't meet a friend's every need, neither can she meet yours. Work on meeting people who share your love of underwater photography or who also enjoy advocating for food free of genetically modified organisms and you'll have a more satisfying life than if you are worrying about what your friends are doing when you're not around.

When you struggle with the idea of your friends hanging out without you, wondering whether they're talking about you or if they even care, you are dealing with a lack of self-confidence. Self-confidence and jealousy cannot exist in the same room. If you build your confidence, the jealousy you are struggling with will have to leave. One way to help build your confidence is to examine how you are interpreting events, says psychologist Leslie Becker-Phelps in a December 2012 "Psychology Today" article. You are using selective interpretation if you choose to believe that your friends are getting together without you because they don't want to be around you. The real reason is likely something else, such as attending the Barry Manilow concert without you because you prefer heavy metal or respecting your need to spend more time with your family.

Jealousy is caused at least partially by fear, says therapist Emily Christensen in a January 2013 article on FamilyShare.com. To eliminate jealousy, you'll need to have the courage to face your fear and call it out for the lie it is. For example, if fear is telling you that your friend doesn't value your company as much because she attended another friend's art opening without you, acknowledge it. Then question whether the fear is realistic. Most often, it is a product of insecurity rather than reality.