Those who stutter may not always stutter in every situation. Though anxiety provoking situations will most often cause someone who sutters to stutter in that moment.  When we are anxious our thinking is not clear and our body may begin to tense up in various areas. With the lack of clear thought and tension this may cause you to sutter as it is more difficult to be mindful of words that are difficult to produce and strategies you typically use to be used in those moments. The added tension which can also occur around the mouth area may also cause you to sutter as your muscles tense up and become difficult to relax.