Blocked salivary gland ducts are caused by salivary stones, infections, cysts and tumors. Issues arise when salivary glands are blocked, causing problems with swallowing, lubricating the mouth, digestion and bacterial infection of the teeth, states WebMD.
Salivary glands produce about 1 quart of saliva daily. There are three major pairs of salivary glands, the parotid glands inside the cheeks, the sublingual under the tongue, and the submandibular glands on the floor of the mouth, according to WebMD. Hundreds of minor salivary glands are located around the mouth and throat.
Salivary stones called sialoliths are the most common causes of salivary gland swelling. Sialoliths consisting of crystallized saliva block the flow of saliva and if not cleared from the gland, cause salivary gland bacterial infection, sialadenitis, characterized by a painful lump, foul-tasting pus discharge, high fever and abscess, states WebMD.
Viral infections cause swelling of salivary glands. Mumps cause salivary gland swelling about 48 hours after the onset of fever and headache. Other viral infections, such as human immunodeficiency virus, Epstein-Barr and cytomegalovirus also are triggers of glandular swelling. Cyst formations interfere with eating and speaking. Cysts are the result of injuries, sialoliths, tumors or infections. Tumors are either cancerous or benign, says WebMD.