There are pretty clear signs that someone is having anxiety at the moment of the stutter that every psychiatrist is trained to notice. (Eye contact avoidance, pressured speech, unexpected pauses or other body movements, etc ). Many SLPs with advanced training in dysfluency (who are/were also severe stutterers) will tell you the same thing that psychiatrist said - social anxiety + trying to not have repetitions will lead to blocks and avoidance behaviors. To conform my claims, I’m linking a previous post with many links of professionals with advanced training who are formally respected within the SLP community. It also gives tangible steps on how to improve things for yourself. Let me know if you have any questions :)