We said above that anger is a sort of transformation of pain, a category including fear feelings as well as physical pain. Considered physiologically (from the perspective of the body), there are a great number of common characteristics shared by anger and fear. Both emotions are characterized by similar central nervous system arousal. In large part, it is our psychological interpretation of arousal feelings that determines whether we will feel fear, anger, or a combination of both.
Think about your own experiences with fear and anger. What does it mean when you experience that sinking feeling in your stomach, sweat on your brow and nervous palpitation of your heart? These physiological symptoms can be signs that you are afraid, angry, or both. In fact, it can be difficult to tell anger apart from fear if you discount the presence of anger-triggering thoughts. In order to determine what specific emotion you are feeling, you need to examine the contents of your thoughts. What you are thinking is the surest way to figure out whether you are primarily angry or afraid.
Though very similar, the physical manifestations of anger and fear are not entirely identical. While heart rate goes up in both anger and fear, skin temperature and electrical conductance (how easily your skin conducts a mild electric current) react differently, increasing when you are angry, and decreasing when you are frightened. This is why some people say they are “hot headed” when angry and “cold and clammy” when afraid. It is not always the case that angry people get hotter and frightened people get colder, however, so paying attention to how anger and fear affect you personally is a good idea. You'll be able to use this sort of information to better manage your anger.