Mouth sores are painful lesions that form in the oral soft tissues, including the lips, gums, tongue, cheeks, the floor of the mouth, or the roof. There are many things that can lead to mouth sores, ranging from common injuries to serious health conditions. Some common causes of mouth sores include:

• Biting your lip, tongue, or cheek.
• Irritation from braces or other orthodontic devices.
• Brushing your teeth too hard or using a hard-bristled toothbrush.
• Using tobacco products.
• Hormone changes.
• Stress.
• Burning your mouth on hot food.
• Exposure to the herpes simplex virus.

There are also many diseases and health conditions that can cause mouth sores to develop, including mononucleosis, celiac disease, anemia, folate deficiency, hand, foot and mouth disease, pemphigus vulgaris, HIV and AIDS, lupus, Crohn’s disease, irritable bowel syndrome (IBS), and HPV (human papilloma virus) . People who are undergoing cancer treatment may develop mouth sores as well, especially those receiving radiation therapy to the head or neck.

Canker sores are a common type of mouth ulcer that can appear on the gums, tongue, roof of the mouth, inner cheeks, or inner lips. They are usually white or yellow with red around the edges and can be extremely painful. The exact cause of canker sores is unknown, but they can be triggered by minor trauma (like biting your cheek), acidic foods, and even stress. Other types of mouth ulcers include oral thrush, which is caused by an overgrowth of yeast called Candida albicans, and mouth ulcers caused by mouth cancer.

In many cases, the reason for mouth ulcers is unclear, but most single mouth ulcers are caused by damage to the lining inside the mouth. Mouth ulcers are usually harmless and most clear up by themselves within a week or two. However, a long-lasting mouth ulcer can be a sign of mouth cancer, which is why its important to detect it as early as possible. If you have a mouth ulcer that doesnt go away, unexplained numbness in the face, mouth, or neck, or problems chewing, speaking, or swallowing, you should see a doctor.