A "hell realm" in Buddhism is like hell in Christianity, except it is not forever. Souls stuck in a hell realm will eventually see their suffering eased. (Just for all you doctrine checkers, I don't believe in a God-created hell.) So the Buddhist concept is much more useful for organizing one's spiritual landscape, since it clearly symbolizes what happens to someone who is stuck in a hellish existence of their own and their environment's making. The person experiences what seems to be an inescapable horror - Hell. The essence of Christianity is to know that God's love can free anyone, and that hellish conditions can end.
So what do you do for a person who is stuck in a hell realm? What does that person's life look like?
The clearest cases are people in the midst of a panic attack. They become increasingly anxious and fearful that something unbearable (like dying) is happening to them, or about to. They are inconsolable, and cannot think logically. They may act irrationally or threateningly. They can be scary to be around. (At least, that's how my panic attacks were.) They need either intense kindness and reassurance from whoever is with them, or to be taken to a hospital.
A panic attack is an acute hell realm. But a chronic hell realm can be just as bad. It is a thought that recurs frequently, and it is unbearable, so it is pushed back from consciousness. The process of that thought's occurrence, and the instant reaction of pushing it away, constitutes what we call emotional pain.
The thought will consist of seeing oneself in a negative light. Like, "I'm fat and ugly." "I might fail again, and prove thereby that I am doomed/cursed." "Someone else is winning, and I'm losing." "People hate me or want to hurt me or don't care about me." The specific situation elicits the thought, and it is instantly pushed under conscious awareness. But the associated feeling lingers, and the feeling is pain. The thoughts that go through the thinker's mind are suspicions or despairs about the intentions of the people you are with. Like "That person thinks I'm fat and ugly," or "I am being cheated."
Feeling under threat or angry toward people you know to be your friends is a pretty clear sign of a negative self-image that must be pushed away. The key phrase there is "people you know to be your friends." A friend is defined as someone who loves you and wishes you well. But you are thinking both that a person is a friend, and that they don't wish you well. If you are holding that contradiction in your mind, you are in pain. If you know the person to be a friend, and you think they want to hurt you, then in this moment you have had one of the worst experiences - possible loss of a friend. On a subconscious level, you can have this experience over and over and over in a single conversation. What the other person does or thinks has very little to do with all this bad experience. You suffer as long as you can't accept the possibility of some reality - like, maybe you really are fat and ugly. So what? If you are aware of it, you can take better evasive action than if you aren't.
All this can happen under the surface of ostensibly logical conversation. In this case, logic is pointless. No communication is going to help, unless it gets through you that you are loved. The less able you are to see love coming toward you, the more intense the hell realm.