When flow of saliva through the salivary gland slows down material in the duct can form stones. These stones block the outflow of saliva, causing swelling and pain in the gland. Stones can form in any of the major salivary glands. These include the parotid gland and the submandibular gland.
Symptoms suggestive of stones should be evaluated by an ear, nose and throat physician that specializes in salivary gland disease. You should have a careful examination and may also have a CT scan done to confirm the presence of a stone.