Finding a bump under your lip is common. These small, raised areas vary in color or texture. While many are harmless and resolve on their own, understanding potential causes helps determine if medical evaluation is needed.
Common Benign Reasons for a Lip Bump
A frequent cause of a lip bump is a mucocele, also known as an oral mucous cyst. These fluid-filled swellings typically appear on the inside of the lower lip, often resulting from trauma like biting or sucking, which damages a minor salivary gland duct. Mucoceles are usually soft, round, and dome-shaped, 2 to 10 millimeters in diameter, with a pearly, semi-clear, or bluish appearance. While generally painless, larger ones can cause discomfort when speaking or eating. Most resolve spontaneously within a few weeks, though some may persist or enlarge.
Another common culprit is a canker sore, or aphthous ulcer, forming on soft tissues inside the mouth. These sores appear as white or yellowish open wounds surrounded by a red, inflamed border. Canker sores are not contagious and often cause a tingling or painful sensation, especially when eating or speaking. While their exact cause is unknown, factors like minor mouth injuries, stress, hormonal changes, or nutritional deficiencies (such as low iron or vitamin B12) can trigger them. Most heal on their own within one to three weeks.
Fordyce spots are another benign reason for small bumps on the lips. These enlarged oil-producing sebaceous glands appear as tiny, painless white or pale yellow bumps, typically less than 3 millimeters wide. They are a natural part of the skin’s anatomy, present at birth, and become more noticeable during puberty due to hormonal changes. They affect a large portion of the adult population, estimated between 70% and 90%.
Minor trauma or irritation can also lead to temporary bumps under the lip. This can occur from repeatedly biting the lip, vigorous brushing, or contact with sharp teeth. Such irritation can cause localized swelling, redness, or small cuts, which typically resolve as the tissue heals.
Other Potential Explanations
Beyond common benign issues, other conditions can cause lip bumps. Oral fibromas, also known as irritation fibromas or reactive hyperplasia, are firm, smooth, raised nodules of connective tissue that develop in response to chronic irritation or trauma. These can be pink or white, depending on their location, and often measure 1 to 2 millimeters, though they can grow larger over weeks. Common causes include compulsive lip or cheek biting, ill-fitting dental appliances, or rough teeth. While generally non-cancerous, their appearance can resemble other conditions, sometimes necessitating a biopsy for confirmation.
Sebaceous cysts, often referred to as epidermal inclusion cysts, are fluid-filled sacs that form under the skin when a sebaceous gland or its duct becomes blocked or damaged. These cysts typically appear as round or dome-shaped lumps, sometimes with a dark dot in the center, and can range from 0.25 inches to over 2 inches in size. While they usually grow slowly and are painless, they can become uncomfortable if inflamed.
Allergic reactions can also manifest as sudden swelling or bumps on the lips. This can be a response to various allergens, including certain foods, ingredients in lip products like lipstick, or even pet dander. The reaction can lead to inflammation, itching, redness, or scaly skin. Symptoms often appear quickly after exposure and typically subside once the allergen is avoided.
While rare, more serious conditions such as early stages of oral cancer can present as persistent sores or lumps on the lips that do not heal. These may also involve changes in color, becoming red or white patches, or lead to numbness, bleeding, or pain. Such bumps warrant prompt medical attention for proper diagnosis.
When to Consult a Doctor
While many lip bumps are temporary and harmless, certain signs indicate professional medical advice is needed. Consult a doctor if a lip bump:
Persists for more than 1 to 2 weeks without healing.
Shows noticeable changes in size, shape, or color, or begins to bleed.
Causes severe or worsening pain, or shows pus, redness, or warmth (suggesting infection).
Leads to difficulty eating, speaking, or swallowing.
Is associated with fever, swollen lymph nodes in the neck, or jaw swelling.
Self-diagnosis is not a substitute for a thorough examination by a dentist or doctor, who can accurately identify the cause and recommend appropriate steps.
General Care and Prevention
For minor lip bumps not indicative of a serious condition, several general care practices can aid healing and prevent recurrence:
Maintain good oral hygiene, brushing teeth two to three times daily and flossing at least once a day. If an infection caused the bump, replace your toothbrush after treatment to prevent re-infection.
Avoid habits that irritate the lips, such as biting or sucking on them, to prevent mucoceles and oral fibromas.
Be mindful of potential irritants in oral care products, like toothpastes containing sodium lauryl sulfate, especially if prone to canker sores.
Apply a cold compress to the affected area to reduce swelling and discomfort.
Rinse the mouth with a warm saltwater solution (about one teaspoon of salt in 8 ounces of water) to minimize inflammation and keep the area clean.
Use over-the-counter pain relievers to manage any associated pain or discomfort.
Stay hydrated and consume a balanced diet rich in vitamins and minerals to support overall oral health and immune function.