Cheating in a relationship can take several different forms. In his research study “Infidelity in Committed Relationships,” Adrian Blow, Ph.D., L.M.F.T., notes that cheating encompasses intimacy of various types, such as an Internet relationship sparked via Facebook, a relationship with someone at work or a long-distance phone relationship. The effects of cheating can bring many negative elements into a relationship.

Guilt and Shame

More often than not, an individual who has cheated feels regret and is remorseful over what has been done. If the infidelity has not been found out, it may eat at the individual from the inside -- this effect being compounded if lies have to be told to help cover up the guilt.

Betrayal and Mistrust

Cheating can inject feelings of mistrust into a relationship. According to research conducted by Richard D. McAnulty, Ph.D., and Jocelyn M. Brineman and presented in the 2007 article "Infidelity in Dating Relationships," individuals who have been cheated on feel betrayed. They may find themselves constantly wondering whether or not the infidelity will occur again, as well as in what other ways their partners will betray their trust. This inevitably disrupts the balance of harmony in the relationship, making an already difficult situation much worse.

Hurt and Anger

McAnulty and Brineman found that even in relationships that were already experiencing difficulties, those cheated on still felt hurt and brokenhearted over the fact that their partners gave affection to someone else. This hurt can often be expressed in anger and lashing out, as the betrayed attempts to cope with the situation.

Forgiveness and Reconciliation

When a relationship has experienced cheating, there is the possibility of the betrayed partner forgiving the one who has cheated and attempting some form of reconciliation and healing. Some relationships do survive cheating. The success of this will depend upon how far the other person went in giving affection or attention to someone else along with how committed the two individuals involved are to each other and their relationship.

Retaliation or Termination

Unfortunately, as McAnulty and Brineman found, some betrayed partners attempt to get revenge by trying to hurt their partners in the way that they were hurt. Some may begin to flirt more with others and may even go as far as to cheat. Whether or not this is the case, many relationships that have experienced cheating eventually end, either through failed attempts at reconciliation or the inability or unwillingness of one partner to deal with the betrayal.