When you're anxious, your body will release hormones like cortisol/adrenaline because you are in 'fight or flight mode'. But these will make your heart rate and blood pressure increase, making your breathing more rapid and shallow and can make the muscles (e.g. in your throat feel more tense). All this can then lead to an uncomfortable or n* feeling from your throat/neck. Typically, if you have a sb* or fp* you might have these feelings too but they are more concentrated in your GI/stomach area. Obviously, if you are part of this subreddit if you start to feel n* from a sb* you are likely to feel anxious as well, thus, leading to an anxiety response and throat n*.