There are three general types of jealousy, according to Kelly DeVere, a licensed and board certified family therapist. These are: reactive jealousy, a reaction to a real event; suspicious jealousy, based on fear or worry; and delusional jealousy, an obsessive intensification of either reactive or suspicious jealousy. Jealousy is a classic sign that a man may be an abuser, warns Northwestern University Women's Center. Even minor episodes of jealousy should be viewed in that light. Suspicious and delusional jealousy are often used by abusive partners to separate the victim from friends and family, as well as to establish and increase control over a partner. Abusers often justify abusive or controlling behaviors arising from their jealousy by blaming their victims.

When a guy gets jealous easily and is quick to accuse you of being unfaithful over even the most insignificant interactions with other men, it could be a sign of his own infidelity. Getting away with his own cheating makes him suspicious of what you could be doing that he doesn't know about. The jealousy can also stem from guilt or other feelings relating to his cheating that the man defends himself against using projection, a Freudian defense mechanism, explains Dr. Russell A. Dewey -- the jealous man treats his partner as if she is guilty of the infidelity he is committing.

Jealousy often relates to low self-esteem and similar self-perception disorders. Jealousy rooted in poor self-esteem is often destructive. Low self-esteem can make it difficult for a person to believe anybody could truly love him. It can seem simply inevitable that his partner will replace him with somebody better, a person with the qualities he thinks he lacks, explains Dr. Suzanne B. Phillips, an adjunct professor of clinical psychology at Long Island University. Others are often viewed as threats to the relationship, leading to jealous questioning and accusations.

A man that gets jealous easily may feel insecure in the relationship. This is common in the beginning of a relationship, such as when one person sees the relationship as exclusive and the other hasn't yet arrived at that point. Insecurity may stem from a lack of shared definitions, including basic concepts such as love and fidelity. Insecurity can also arise later in a relationship. Work or other obligations can consume more time than usual or a couple may be starting to drift apart. Open communication that produces shared expectations and definitions can help resolve these sorts of insecurities and reduce jealousy.