A very red circle under the gums can be caused by gingivitis, food irritation, mouth ulcers and herpes stomatitis.
1. Gingivitis: dental calculus, plaque, food filling and other reasons, may cause an inflammatory reaction of the gums, which leads to the symptom of a very red circle under the gums.
2. Food irritation: Taking harsh and spicy foods, as well as foods that are too hot, can also irritate the gums, leading to a red circle under the gums.
3. Mouth ulcers: Mouth ulcers can also lead to ulcers on the top of the gums, which may also show up as a red circle under the gums.
4. Herpes stomatitis: This is caused by a herpes simplex virus infection, which can lead to ulcers on the top of the gums, and can also lead to a very red circle under the gums.
There may be other reasons for the redness under the gums, and you need to go to the hospital first to get a clear picture of the cause.