Saliva obstruction—Saliva flow can be blocked in the parotid and submandibular glands or ducts either by stones or narrowing inside the ducts. A blocked saliva duct can lead to pain and swelling of the saliva gland. Typically, the glands will swell during a meal for a few minutes before gradually subsiding, only to enlarge again at the next meal. Infection with severe pain and swelling can develop if the gland is blocked for a long time without the ability to release the built-up saliva. If persistent gland swelling is left untreated, the glands may develop a severe infection or abscess.
You may experience a swelling or enlargement of nearby lymph nodes with salivary blockage. These lymph nodes are the structures in the upper neck that often become tender during a common sore throat. In fact, some of these lymph nodes are located on or deep within the parotid gland, or near the submandibular glands. When these lymph nodes become enlarged from infection, you may have a red, painful swelling in the area.
Tumors—Cancerous (malignant) or noncancerous (benign) tumors usually show up as painless lumps or enlargements. Tumors rarely involve more than one gland and are detected as a growth in the parotid, submandibular area, on the palate, floor of mouth, cheeks, or lips. An ENT (ear, nose, and throat) specialist, or otolaryngologist, should check these enlargements.
Cancerous tumors of the major salivary glands can grow quickly, may be painful, and can cause loss of movement in part, or all, of the affected side of the face. These symptoms should also be checked immediately by an ENT specialist.
Other disorders—Enlarged or inflamed salivary glands can also be caused by autoimmune diseases, such as HIV and Sjögren’s syndrome, where the body’s immune system attacks the salivary glands. Dry mouth or dry eyes are symptoms of Sjögren’s syndrome. This may occur with other systemic diseases, such as rheumatoid arthritis. Diabetes may cause painless enlargement of the salivary glands, especially the parotid glands.