Psychologists usually define suppressed anger as anger that is not expressed or dealt with at the time of its occurrence. In some cases, suppressed anger isn't even felt at the time of its occurrence, and, in extreme cases, the cause of the anger itself may be eradicated from conscious memory. People may suppress their angry feelings because they feel that getting angry is wrong, and may struggle with guilt about experiencing the emotion. Some people, especially those with a history of trauma or abuse, may stifle feelings of anger because they felt it was unsafe to express those feelings at the time they originally occurred. Many psychologists believe that repressing anger can lead to mental and physical illness, and that it's therefore important to acknowledge this anger and cope with it.
People who struggle with suppressed anger often have problems dealing with anger in healthy ways. Psychologists generally think that anger can be a healthy feeling, when coped with properly. Those who repress their anger usually don't know how to express these feelings in constructive, rather than damaging, ways. They may fear that expressing their angry feelings will cause further conflict and damage, and so they may refrain from constructive verbal expression of these feelings.
Instead of confronting whoever caused the angry feelings, people who suppress their anger may refrain from saying anything at all. They may pretend that they aren't angry, while continuing to dwell on the injustice done to them and the angry feelings they're experiencing. Repressing anger in this manner can lead to violent outbursts, passive-aggressive behaviors, and resentment. It may also contribute to sleep disorders, depression, high blood pressure, and cardiovascular disorders.
If the situation that caused angry feelings is particularly severe, the person may not even realize he is suffering from suppressed anger. This is particularly common among survivors of child abuse or other victimization. Expressing anger constructively in such a situation is often impossible, and can make the situation more dangerous for the victim. Instead, victims of child abuse and similar trauma learn to hide their angry feelings, even from themselves.
Just because a person suppresses anger over one specific situation, it doesn't mean that they will suppress all of their anger over every annoyance. If the habit of repressing angry emotions was formed early in life, however, the person may struggle to deal with anger well into adulthood. Anger that is expressed at a moment of injustice and then seems to dissipate is usually defined as normal, healthy anger. Anger that appears for no reason, or seems out of proportion with any identifiable, present cause, is typically defined as suppressed anger. Such anger often has its roots in past events.