There are two types of anger you might experience in life and both are perfectly valid.
The first kind is what I'll call sudden anger. It's not logical at all, it's always abrupt, and it's perhaps even a little out of control. When you stub your toe on the way to the bathroom in the morning and it hurts like the dickens, that's sudden anger. No one has hurt you, there is no subtlety and no conflict. Your toe hurts and you respond--ouch! That type of anger will subside after a few minutes and you'll go back to your normal mood.
The second is what I'll call righteous anger, which is perfectly legitimate and also warranted. You haven't stubbed your toe but maybe someone forwarded an email about your work performance that was not true or you found out you're the subject of some office gossip. Righteous anger lasts much longer, maybe even for days or weeks.
(By the way, there's also unnecessary anger which is what happens when a crazy person decides to swear at you for no reason in traffic or when a colleague is always cranky. This is a completely different category and might require professional help.)
We're emotional beings, and stifling the anger emotion is not healthy. With sudden anger, there's some interesting science involved. It's related to a hormone in your body that causes you to react (known as flight or fight). If you're angry about stubbing your toe, it's because your body is wired to warn you about the danger.
Righteous anger is more delayed and sustained, and it's something that will come up frequently in the workplace. It's not related to hormones and goes much deeper into your psyche. It's related to your identity, success in life, work performance, connections you have with others, and even what makes you tick. Righteous anger requires effort on your part since you have to keep ruminating on it. There's no imminent danger.
I used to have a bigger problem with this type of anger than I do now. Righteous anger sometimes lingers too long and turns into bitterness and can make you a difficult and toxic person. It's the difference between being someone who gets angry over a situation, solves it, and goes back to normal and someone who is known as being angry and bitter.
That's where the real challenge comes into play. Some anger is warranted. The truth is that you were slighted or you did have good reason to be upset. Someone did spread gossip. The email did make unfair claims. How you deal with righteous anger is a sign of your character, experience, and maturity level.
I used to react poorly to all types of anger. My advice--and this is what I've learned to do over the years--is to solve anger by choosing to have empathy. It might sound simple, but it works for me and has for many years.
The idea is to switch your perspective. When you only see how you've been slighted and ponder that in your head over and over again, it turns toxic. In any situation, you can change the perspective to the other people involved. Maybe they were totally wrong. However, there is usually something valid about their perspective even if there is only a small sliver of validity. The point here is not to be a doormat. It's more important for your own self-worth and identity to stop lingering on how you've been hurt, mostly as a way to deal with resentment and to start coming up with a solution and a plan. Be careful before you respond in anger and send off that email to vindicate yourself or confront that person.
Instead, start with empathy--what caused the anger and who is involved, what was the perspective of your colleagues, what is motivating them. When you have empathy, it's like a Teflon coating that helps you avoid seeing only how you've been hurt. It helps you resolve conflicts and deal with anger. It's freeing because it's no longer all about you.
Ultimately, that's effective because you can take yourself out of the equation, and that means you are much more equipped to reach a resolution and dispel the anger. You become known as a person who has dealt with anger; it has not defined you.
I've been able to deal with anger in this way, even recently. The righteous anger rises to the surface, but by changing my perspective, it lifts and cools much faster.
If you start dealing with anger in this way and you find it's also effective, please drop me an email after you've experienced some success.