It's not unusual to feel insecure from time to time, but regularly feeling insecure in your relationship can cause damage. Insecurity in a relationship indicates a fear that your significant other will replace you or end the relationship for another reason, says William Berry, a psychotherapist and author of "Insecure? It Has Its Benefits" on Psychology Today. It can be exhausting for your partner to reassure you of your self-worth and his devotion, love and desire for you. The ability to recognize the symptoms of insecurity can enable you to make positive changes to benefit your relationship.

Nonverbal Communication

Your body language, which includes facial expressions, gestures and posture, influences how other people perceive you, says Leonard Mlodinow, author of "How We Communicate Through Body Language" on Psychology Today. The way you interact nonverbally with your girlfriend could be an indication of insecurity in your relationship. Nonverbal cues can get your message across without using words, says HelpGuide.org in "Nonverbal Communication." For example, you might hang on your girlfriend or be in very close proximity to her when you are out. You might make a facial expression of displeasure if an attractive man initiates a conversation with her or step between them.

Jealousy

Jealousy stems from feeling insecure, says Dr. Pepper Schwartz, a professor of sociology at the University of Washington in Seattle, and author of "Are You the Jealous Type?" on the AARP website. The idea of your girlfriend talking to her ex-boyfriend might make your head spin. You might feel threatened, though there's no indication that you should. You might not like her working with male co-workers because you're afraid that she might fall for one of them.

Being Defensive

Defensiveness can be a result of insecurity, says the website Kellevision in "On Being Defensive." Your girlfriend might be overly sensitive and not be able to take teasing well. For example, you may lovingly tease her that her hair is a mess and she might take it personally. You might point out a pimple on her chin and she might storm off. The defensiveness does not come from what is being said, it comes from insecurity a person feels inside, says Kellevision.

Lack of Confidence

Most insecure people display a lack of confidence without even realizing it, says Dr. Gerald Stein, a psychologist and author of "Signs of Insecurity: Behavior That Reveals a Lack of Confidence" on his website, Dr. Gerald Stein. For example, you may not accept compliments well. Your boyfriend may tell you that you are beautiful and you dismiss it or give a reason why it isn't true. You may regularly need assurance from your boyfriend that he loves you and ask for reasons he finds you desirable. If you were self-confident, you wouldn't need for your significant other to quell your doubts of your desirability or self-worth, says Stein.