Hi. Welcome to HEALTHCARE MAGIC.. I have gone through your query and can understand your concerns.. As per your complain swollen gland under the tongue which gets regressed on relaxation indicates that you have clogged duct of salivary gland and in case if it is over any one of the side of tongue it can be clogged submandibular salivary gland while if it is in the region of floor of mouth below lower front teeth it can be due to clogged duct of sublingual salivary gland and the blockage occurs either due to some foreign body or`due to formation of crystalline stones from the minerals present in saliva.. Both these glands are major salivary glands.. You need not to worry and consult an Oral Physician and get evaluated and an MRI or CT SCAN can help in diagnosis.. In case of blocked ducts, if the stones are small taking plenty of sour candies and sugar free chewing gums can stimulate saliva flow and the stones or obstructing foreign body can flush out the stones along with the saliva flow.. In superficial stones the doctor can palpate over the stones and pus towards the duct orifice and remove the stone.. In case of large stones and deeply located surgical removal can be done by making an incision near the stone.. A technique known as SIALOSCOPY which is an endoscopic technique can be employed to locate the deeper stones and subsequent removal.. Hope this information helps.. If you find the answer helpful please give me a Five Star Review and click on found the answer helpful as a token of appreciation.. Thanks and regards.. Dr.Honey Nandwani Arora..