When you get angry, your heart rate and blood pressure go up, as do the levels of your energy hormones, adrenaline, and noradrenaline. People who are easily angered generally have a low tolerance for frustration, meaning simply that they feel that they should not have to be subjected to frustration, inconvenience, or annoyance. They can't take things in stride, and they're particularly infuriated if the situation seems somehow unjust: for example, being corrected for a minor mistake.

Anger is a healthy, normal emotion. It is "an emotional state that varies in intensity from mild irritation to intense fury and rage" accompanied by physiological changes such as palpitation, and hyperventilation (heavy breathing). It is a natural, adaptive response to threats which inspires powerful, often aggressive, feelings and behaviors, which allow us to fight and to defend ourselves when we are attacked (flight or fight). A certain amount of anger, therefore, is necessary to our survival. However, it becomes problematic when it is uncontrollable, or not expressed.

There are 2 types of anger: Attributed anger and Instrumental anger.

Instrumental anger occurs as a result of the person (e.g., the driver of a car being frustrated in an attempt to achieve a goal. Attributed anger occurs as a result of hostile interpretations of ambiguous events. (The driver is cut off by another vehicle and sees this as a personal attack). Consider, for instance, a slow moving car in the your lane. Why is the driver going so slowly? You can attribute the cause to the traffic situation. You might think that the car is old or malfunctioning, or perhaps there is a child in the car, or someone is sick. But a driver with road rage attributes it to the driver's disposition. He might think that the person is inconsiderate, incompetent, stupid, dumb. Or he may attribute it to the driver's appearance, such as race, gender, age, or ethnic background.

A variety of both conscious and unconscious processes can be used to deal with angry feelings in a healthy manner. These include expressing, suppressing, and calming.

Expressing angry feelings in an assertive—NOT aggressive—manner is the healthiest way to express anger. Being assertive does not mean being pushy or demanding; it means being respectful of yourself and others,  making your needs clear, and getting them met without hurting others.

Anger can be suppressed, and then converted or redirected.  The aim is to hold back your anger and convert it into more constructive behavior. The danger is that if it not redirected properly it can turn inward— causing severe stress or depression.

Angry people tend to feel that they are morally right, that any blocking or changing of their plans is an unbearable indignity and that they should NOT have to suffer this way. Maybe other people do, but not them! Anger also affects risk tolerance.

Risk tolerance is the amount of risk that one would normally accept when driving.

• Someone with a low risk tolerance takes few chances and drives in a cautious manner.
• People with a very low risk tolerance may drive in an overly cautious way and hold up traffic by not taking acceptable gaps when turning or driving slow enough to delay or hold up others.
• High risk-tolerant people may be overconfident in their skills and abilities and take chances by speeding or they may be seeking the thrill of "being on the edge" and pushing the limits.
• Assertive drivers have a risk tolerance, which is appropriate to the situation and consistent with accepted standards.

Unexpressed anger can lead to pathological expressions, such as passive-aggressive behavior (getting back at people indirectly, without telling them why, rather than confronting them head-on), an anti-social personality, or perpetual cynicism and and hostility with relationship problems.

Some anger is  learned. We are more likely to get angry if we are frustrated and feel stressed, if we are tired, if we tend to hold our feelings inside rather than talk them out.  

A form of anger control disorder called intermittent explosive disorder is characterized by repeated episodes of aggressive, violent behavior with reactions that are grossly out of proportion to the situation. People with intermittent explosive disorder may lose control and attack others causing bodily injury and property damage, feeling remorse, regret or embarrassment after the event. Uncontrollable angry outbursts can also be a sign of  Borderline Personality Disorder, Bipolar Affective Disorder, or Depression. All of these are treatable conditions and  can be treated with medication and counselling, and Cognitive Therapy.