We're often taught from the very beginning that it's not okay to lose control of our emotions. In particular, while showing glee or happiness is perfectly acceptable, showing anger or frustration is especially frowned upon. But psychologists now say that the often perceived as negative emotion of anger could actually be quite positive for your body and mind.
Accepting that you feel angry can be a powerful motivating force. Many times, people can channel their frustration to help push them towards a goal or desire. In addition, by being angry and acknowledging that something is unpleasant in our lives, we may open communication channels that would otherwise be closed. Used constructively, anger can improve relationships with others and with ourselves, as we gain more insight into exactly why we're unhappy. By contrast, suppressing the angry feelings may breed unhealthy resentment and tendencies that don't serve to move us further.
As with anything else in life, moderation is key. So while expressing anger and frustration may be totally healthy, remember that being angry all the time is typically associated with poor health.