How do I know when it's okay to tell someone I'm angry with them and when I'm just picking a fight based on a small disagreement?

The best thing for you is to put yourself in their shoes and see how would you react and that'll give you the answer :)

Sometimes its okay to swallow some issues, and other times, closure and understanding is necessary; relationships, whether between partner and partner, family member and fellow family member, etc. are complex and involved a lot of emotion and communication. When things get out of hand, when issues and concerns arise which come to challenge your internal strength and confidence, its important to act--to stand up for what you feel to be appropriate and right; dont suffer in silence, ever. A relationship needs to be healthy and cooperative, whole and respectful; sometimes petty issues can be resolved easily, other times its necessary to engage in more profound conversations; either way, resolving such issues is crucial for the health and happiness of not on the relationship, but, more so, for yourself.

It is always okay to let someone know how you feel. It matters on the way you tell them. Yelling and such does not help but communicating your feelings calmly is very efficient :)

I think that if you feel very passionate about a problem it is always ok to speak up but if you know the problem is something you will be over soon then it is not worth it

If you feel that your feelings have been hurt or that you've been misunderstood or not understood at all, then you should speak up to that person. Let them know why you feel the way you do. You can talk and be calm and make your statement in a cordial manner. Just let them know how you feel and more importantly "why" you feel the way you do.

If you are angry with someone, you should always tell them. Maybe you feel it is just because of a small matter, but they are the only person that can help you resolve this problem. It is better to tell someone "I'am currently very cross with you, please excuse my harsh demeanor." than acting harshly towards someone without them realising why you are angry with them and then in return becoming angry at you.

It's ok to tell someone that you're angry when you are no longer angry. Because then you won't be confronting with rage, rather with reflection and understanding.

Its always base on the time, place and way you convey the message to them. Make sure that the time and place is appropriate and when you tell that person don't immediately say that you are angry with them. Tell them 1st what is the meeting about and what situation you are referring too then say that that situation made u upset and why.

you should look in yourself what is the level of anger that you feel. how much is it bothering you? if you think that it will go by itself in a couple of days maybe its not worth the fight.