You take a small possibility and follow it, link by link, all the way to the worst imaginable outcome. "If I go to this party, I won't know what to say, and I'll stand there awkwardly, and people will notice, and they'll think I'm strange, and word will get around, and I'll be humiliated." Each link seems plausible, and the chain drags you to disaster. This is catastrophizing, and it is one of the loudest engines of social anxiety.
How the chain works
Catastrophizing assumes the worst at every single fork. Notice that the catastrophe exists only in the future, only in imagination, and it depends on every link holding. But reality rarely cooperates with the catastrophic script. It is far more mundane and far more forgiving. Most feared social events end not in humiliation but in something forgettable, which is exactly why we so rarely remember the disasters we spent days dreading; they mostly did not happen.
The two questions that shrink it
When you catch yourself catastrophizing, ask two questions. First, what is most likely to actually happen? Not the worst case, the likely case. The likely case at the party is that you have a couple of ordinary conversations and leave. Second, if the bad thing did happen, how would I cope? You are more resourceful than your catastrophes assume, and you have survived every hard social moment of your life so far, which is a perfect track record. The American Psychological Association describes exactly this kind of questioning as a core skill of cognitive behavioral therapy (CBT).
Decatastrophizing, not toxic positivity
This is not about forcing false cheer or pretending nothing can go wrong. Sometimes a conversation is awkward; sometimes you are turned down. Decatastrophizing simply right-sizes the fear, replacing "this will be an unbearable disaster" with "this might be uncomfortable, and I can handle uncomfortable." That is both more accurate and more useful. The National Health Service points to this kind of structured thought-challenging, rather than reassurance or avoidance, as what actually helps social anxiety.
Testing your forecasts
Catastrophizing is also a form of fortune telling, and fortune telling is best beaten by evidence. Treat your dark prediction as a hypothesis: "I predict this will be awful. Let me go and find out whether that is true." Over and over, the evidence comes back that the prediction was too dark, and slowly the mind learns to trust its forecasts less. Avoidance keeps the prediction untested and therefore alive; gentle facing disproves it.
Coping ahead instead of catastrophizing
There is a healthy cousin of catastrophizing called coping ahead, and the difference between them is everything. Catastrophizing imagines the worst and stops there, leaving you flooded and helpless. Coping ahead imagines a difficulty and then rehearses how you would handle it, which leaves you steadier. So when your mind insists a social event will be a disaster, you can redirect the same imaginative energy usefully. Picture the specific thing you fear, an awkward silence, say, and then picture yourself handling it: taking a breath, asking the other person a question, letting the pause be. The fear shrinks when it meets a plan, because most of its power comes from the unspoken assumption that if the bad thing happened you would be destroyed by it. You would not. You would cope, as you have coped with every hard social moment so far. Coping ahead also gives your mind something to do with its worry other than spin, which is often what it was reaching for anyway. You cannot stop your brain from running simulations, but you can insist that the simulations end with you managing, not melting.
Catastrophizing usually runs with mind reading and anticipatory dread. For the mind-reading piece, see why you assume people are judging you, and for the complete practice of reframing anxious thoughts, Unjudged.