Hello, I'm Using Medicinal Cannabis, And Often Smoke It But

hello, i'm using medicinal cannabis, and often smoke it but i use a vaporizer too. When i smoke my joint i always smoke them with tobacco, i had a question about it. When i smoke and exhale after each hit i need to spit, when my joint is done i could fill half of a soda can with my saliva, i always was afraid that it was preferable to spit so i always did but can you give me some information if you know anything about it