Possible causes of lumps on the gums include canker sores, oral herpes, oral cancer, salivary duct obstruction, acute sinusitis, esophagitis and pemphigus, according to WebMD. Lumps on the gums may also be harmless mucocele, which form when salivary ducts are damaged or blocked.
Canker sores are accompanied by a tingling sensation, according to WebMD. A canker sore typically starts out as a red bump that develops into an ulcer. Oral herpes is caused by a viral infection, leading to fever blisters opening in and around the mouth. Oral cancer usually begins as a white patch on the inner cheek or gums. Salivary duct obstruction, also called sialothiasis, can manifest as a lump on the gums, usually accompanied by swelling, pain or both. Acute sinusitis can cause lumps to appear on the gums, typically accompanied by pain and tenderness in the sinuses.
Some of the symptoms that accompany esophagitis include chest pain and nausea, according to WebMD. Pemphigus causes blisters to break out on the skin and mucous membranes in the body, including the gums.
Mucocele are harmless cysts that typically go away on their own after a period of time, according to WebMD. They are generally movable, painless dome-shaped lumps with a pearly or semi-transparent surface. Mucocele are often between 2 and 10 millimeters in diameter.