A bump inside your lip is most often a mucocele, a fluid-filled cyst that forms when a tiny salivary gland gets blocked or damaged. These are painless, clear or bluish, and extremely common. But not every bump is a mucocele. Depending on what it looks like, how it feels, and how long it’s been there, the cause could be something else entirely.
Mucocele: The Most Common Cause
Your inner lips are lined with hundreds of minor salivary glands, and when one of them gets injured or blocked, saliva backs up and forms a soft, fluid-filled sac just under the surface. That’s a mucocele. They range from about 1 millimeter to 2 centimeters wide, feel squishy to the touch, and are usually clear or slightly blue. The lower lip is the most common spot, accounting for roughly 74% of cases.
Most mucoceles are painless. You might notice one after accidentally biting your lip, after dental work, or for no obvious reason at all. They sometimes pop on their own, drain, and then refill. The average mucocele sticks around for about four months before a person seeks treatment, though many resolve without any intervention. If one keeps coming back or bothers you, a dentist can remove it surgically or with a laser. Laser removal has a lower recurrence rate and leaves less scarring than traditional excision, which has a recurrence rate around 9%.
Fordyce Spots: Tiny, Painless, and Normal
If you’re seeing clusters of very small white, yellowish, or pale bumps rather than a single lump, these are likely Fordyce spots. They’re visible oil glands sitting just beneath the surface of the mucous membrane, and 70% to 80% of adults have them. Each spot is only 1 to 3 millimeters across, roughly the size of a sesame seed or smaller. They become more noticeable when you stretch the skin around them.
Fordyce spots are completely harmless and not caused by any infection or disease. They don’t need treatment. Many people go years without noticing them, then spot them one day and worry. If that’s what you’re seeing, you can stop worrying.
Canker Sores: Painful Open Ulcers
If your bump is actually a shallow, open sore that stings or burns, especially when you eat acidic or salty food, it’s probably a canker sore. These form on the insides of the cheeks, lips, and tongue. They typically look like a small round or oval wound with a white or yellowish center and a red border.
Canker sores are not contagious. They can be triggered by stress, minor mouth injuries, hormonal changes, or certain foods. Most heal on their own within one to two weeks. If you’re getting them frequently or they’re unusually large, that’s worth mentioning to a dentist or doctor, but the occasional canker sore is a normal nuisance.
Cold sores, by contrast, almost always appear on the outside of the mouth around the lips, not inside. They are caused by a virus and are very contagious. A bump on the inner surface of your lip is unlikely to be a cold sore.
Irritation Fibroma: A Firm, Flesh-Colored Nodule
If the bump is firm rather than soft, flesh-colored or pink, and has been there for a while without changing much, it could be an irritation fibroma. This isn’t a tumor. It’s an overgrowth of connective tissue caused by repeated low-level trauma, like habitually biting or chewing the inside of your lip, or friction from a rough tooth edge or dental appliance.
Fibromas grow slowly and rarely exceed 1.5 centimeters. They have smooth surfaces, well-defined borders, and don’t hurt. They won’t go away on their own, but they’re benign. If one is large enough to be annoying, a dentist can remove it with a simple excision. Recurrence after removal is uncommon as long as the source of irritation is addressed.
Salivary Gland Stone
Less common but worth knowing about: a small, hard, movable lump inside your lip could be a salivary stone. These form when minerals in saliva crystallize and block a minor salivary gland duct. The lump is typically firm to the touch and you can often move it slightly under the surface. One documented case measured just 4 millimeters across.
Salivary stones in the minor glands of the lip are often painless, though they can sometimes cause swelling or tenderness during meals when saliva production increases. Small stones occasionally work their way out on their own. Larger or persistent ones may need to be removed by a dentist or oral surgeon.
White Lacy Patches: Oral Lichen Planus
If what you’re noticing isn’t a discrete bump but more of a white, lacy, web-like pattern on the inside of your cheeks or lips, this could be oral lichen planus. The most common form creates painless white patches that look almost like a delicate net over the tissue. It’s a chronic inflammatory condition, not an infection, and it tends to come and go over time. A dentist can confirm it with a visual exam or biopsy.
When a Bump Needs Attention
Most bumps inside the lip are harmless. But certain features warrant a closer look. A sore or lump that hasn’t healed or changed in two weeks or more, a flat whitish discoloration that won’t wipe away, numbness or tingling in the lip, or a lump that keeps growing are all signs that should be evaluated by a dentist or oral surgeon. Lip and oral cancers are uncommon, especially on the inner lip, but they do present as persistent lesions that don’t resolve on their own.
The texture matters too. A bump that feels hard, fixed in place (rather than movable), or has irregular borders is more concerning than one that’s soft, round, and well-defined. If you’re unsure, a quick evaluation can rule out anything serious. Most of the time, the answer turns out to be a mucocele, a fibroma, or something equally benign.