I don't think anybody's ever angry without reason really. It's just that these things might not necessarily be as surface as we might like it to be. For some people the cause -- or causes -- of their anger is buried deep and as such it is not usually obvious as to why they're angry, which is why iy might seem as though they are just being angry for no reason. If one could only know, there are demons buried very deep that stirs in them and causes these anger.
Also we get angry due to the way we interpret situations. And because everyone is different we all have our ways of interpreting situations that is different from others. So to other people what makes you angry may seem irrational and unjustified, and to them the person might appear to be angry for no reason. Some of the things that may cause anger I'll highlight below and try to show how they're all based on our subjective perceptions.
First. Getting Threatened or Attacked. Like I said we get angry based on the way we perceive and interprete various situations. Now anybody would get angry in a situation where they perceive that they are being attacked or threatened. But it is in the interpretation of this that the quandary lies.
I may interprete a situation where a couple of people converge on me as a threatening one; consequently I may get angry. But this anger becomes irrational to people who are looking on from the outside without the knowledge that the people are trying to harm me. Hence it may seem to them that I am angry for no reason.
Secondly we get angry in situations where we feel powerless. This is one of the really misunderstood and funny occurrences. A man who may seem to irrationally get angry every now and then may just be projecting his powerlessness.
He may feel this inwardly and even though outward everybody thinks he's or ought to be a strong powerful person deep down he's assailed by the thoughts of his powerlessness and tortured by it, and so to hide it he gets angry hoping that his constant anger would make up for his fears.
As you see, even though this may appear to an onlooker as the person getting angry without reason, there actually is a reason, even though it is a really funny one.
Another seemingly funny but really serious reason people get angry is hunger. Yeah it may seem funny at first but it isn't. There is a popular saying that an hungry man is an angry man and personally I've found this to be absolutely true.
Apart from being tortured by the hunger itself you're also tortured and traumatized by the cause of that organ: which will be the fact that you lack the necessary means to provide food yourself and maybe even for your family. And you would agree that a person going through that is definitely not a happy person and therefore tends to get irritated very easily. Just a slight provocation or confrontation can make that person flare up and get really angry.
Other people won't know of course, because we can only feel our own stomachs and not that of others, and so that anger too might appear to be without reason but really is not the case.
Also the way we react to situations may depend on our childhood and upbringing, and since we all have different upbringings and situations we were exposed to as children, we will definitely react to situations differently.
Some might have grown up exposed to a lot of anger, and so might be of the believe that anger is the ubiquitous necessary reactions to all situations. Some might have grown up witnessing series of domestic violence and might picked up a negative thing or two from that formative experience.
So these are just some of the reasons people might get angry, and because we're unable to understand or get the full picture- -and this is not our fault of course--it may seem to us that they are just being angry for no reason. But there is always a deeper underlying cause somewhere.
My next door neighbour gets mad for no reason, he blows his top so fast that you would think that he was dealing with a mob of gangsters as he just goes into fits of rage.
I have a doctor I have to see because of my mental illness and I was talking to her about it and she was telling me that people who get mad for no reason are linked to depression, it is a form of the flight or fight that is built into us.
I think that he is depressed but he won't see anyone about it, I think if he did he would find peace as this is something that is growing inside of him and we see it more often than not.
I have also seen people at work get angry for no reason out of frustration which makes them feel like they have done something wrong and they blow up, this then has a knock on effect. maybe it is something to do with been a child and it is inside them too, but I kind of agree with my doctor, normally depression has its way like this. :D
Some people get angry without reasons. Because they are mad.