Finding a small bump inside the mouth can cause concern, but the vast majority of these growths are benign. The oral cavity is constantly subject to friction and minor trauma, making small, temporary tissue reactions common. These lesions often arise from simple irritation and are generally self-limiting, resolving without intervention. Understanding the characteristics of a bump is the first step toward appropriate care, as the oral environment can also be the site of more serious conditions.
Temporary Bumps Caused by Injury or Inflammation
Many small bumps are the body’s reaction to localized injury or prolonged irritation. One frequent cause is a traumatic fibroma, a benign, scar-like growth of connective tissue. This firm, dome-shaped nodule develops slowly in response to chronic trauma, such as repeatedly biting the cheek or constant rubbing from a rough tooth or dental appliance. Traumatic fibromas are typically painless and usually match the color of the surrounding cheek lining.
Another common temporary bump is an aphthous ulcer, or canker sore, which is an inflammatory sore that feels like a distinct bump before it fully ulcerates. These sores typically present as a painful, round or oval lesion with a white or yellowish center surrounded by a distinct red border. Minor aphthous ulcers are small, generally less than 10 millimeters in diameter, and heal on their own within 7 to 10 days. They frequently appear on the inside of the lips, cheeks, or under the tongue, and can be triggered by minor local trauma, stress, or certain food sensitivities.
Bumps Related to Salivary Glands and Ducts
A different class of bump arises from the minor or major salivary glands, often presenting as a soft, fluid-filled swelling. A mucocele is a common type that occurs when a minor salivary gland duct is ruptured, typically due to lip biting or trauma. This causes mucus to leak out and pool in the soft tissue, forming a cyst-like swelling. Mucoceles are most frequently found on the inner surface of the lower lip, presenting as painless, movable, dome-shaped swellings that may appear bluish or translucent.
A ranula is a specific type of mucocele that develops on the floor of the mouth, involving the major salivary glands, most often the sublingual gland. Ranulas are generally larger than other mucoceles and can sometimes interfere with swallowing or speaking.
Harmless and Permanent Anatomical Structures
Some structures are normal variations of oral anatomy that are frequently mistaken for growths. These structures are hard, permanent, and represent a localized bony overgrowth, known as exostoses. Torus palatinus is one example, presenting as a hard bony lump located along the midline of the hard palate, or roof of the mouth.
Mandibular tori are similar bony growths that appear on the inside surface of the lower jaw, usually near the premolar teeth. These tori are slow-growing, firm to the touch, and can occur on one or both sides of the jaw. They are typically painless and are only treated if they interfere with dental appliances, speech, or function.
Recognizing Warning Signs and Seeking Medical Advice
While most oral bumps are benign and resolve on their own, a professional evaluation is necessary for any lesion that does not follow a typical healing pattern. A bump or sore that persists for longer than two to three weeks is a primary warning sign that warrants attention from a dentist or physician. Other specific red flags include any thickening or lump that is rapidly growing or that causes unexplained numbness in the mouth or face.
Changes in color or texture, particularly the development of persistent white patches (leukoplakia) or red patches (erythroplakia) that cannot be easily scraped off, should be evaluated promptly. Difficulty swallowing, persistent hoarseness, or any unexplained bleeding from the mouth are also symptoms that indicate the need for a thorough clinical examination. The healthcare provider will visually inspect the area and, if necessary, perform a biopsy to definitively determine the nature of the growth.