According to WebMD, a person produces between 2 and 4 pints of saliva on a daily basis. The most saliva is produced during the late afternoon hours.
Health issues sometimes affect saliva production leading to conditions such as a dry mouth. Dry mouth, in turn, has the potential to cause swelling and discomfort of the gums and tongue. Germs can also multiply in a dry mouth, creating problems with bad breath. Some medicines affect saliva production, especially diuretics and antihistamines. Structural problems with salivary ducts can affect production. Diseases such as diabetes and AIDS sometimes also lead to dry mouth problems.