Why do we swallow our saliva when we are afraid?

sympathetic nervous system of the ANS is activated when scared/panic causing production of small amounts of thick mucin rich saliva. Strong stimulation of the sympathetic NS constricts the blood vessels supplying the salivary glands thus inhibiting saliva release leading causing dry mouth. read more

Yes, we do swallow regularly in our sleep. Also let me assure you, there is no danger at all of choking on our saliva during sleep. I am an ENT (ear, nose, throat) specialist and can assure you of this. It is simply impossible. The throat has a reflex called swallowing reflex which automatically swallows any saliva once it touches the pharynx. read more