The evaluation of mouth ulcers begins with a history and physical exam.

Physical findings in someone with mouth ulcers may include:

• Open sores in the mouth
• Mouth swelling
• Throat redness
• Swollen glands in the neck
• White discoloration to the lining of the mouth

Testing is not required to make the diagnosis of mouth ulcers. Testing may be required to exclude mouth cancer.

Tests that may be used to evaluate mouth ulcers include:

• Throat culture
• Biopsy of a mouth ulcer
• Complete blood count
• Dental and jaw x-rays
• Soft tissue x-ray of the neck