Whether or not a hard lump under the tongue can heal on its own depends on the specific situation, if it is caused by physiological factors, it is normal and does not require special treatment, if it is caused by pathological factors, it will not heal on its own and requires timely medical treatment. Under normal circumstances, there will be small bumps under the tongue, mainly distributed in the left and right sides of the tongue ligament, is the submandibular gland ducts, sublingual gland openings are located in the position of the sublingual folds and sublingual caruncle, it is a normal phenomenon, do not need to be treated. If a large, blister-like lump suddenly appears under the tongue, it is possible that a mucus cyst has formed locally. Mucus cysts can rupture, and if rupture occurs repeatedly, a hard keratin will form, which needs to be surgically removed. In addition, the appearance of lumps under the tongue may also be the emergence of submandibular gland, sublingual gland duct stone, this should also be surgically removed. If there is localized pain, redness, swelling and ulceration when a hard lump grows under the tongue, you should go to the hospital and get treatment in time.