Hello Causes of recurrent mouth ulcers are Excessive smoking and chewing tobacco B12 deficiency Iron deficiency Coeliac disease Immunodeficiencies Folate deficiency Irritable bowel syndrome  Use of medicines like pain killers or beta blockers etc. Apart from the common mouth ulcer there is another ulcer known as aphthous ulcer. Their appearances are related to the mental stress of the person. They have some connection with puberty and are hereditary. They tend to last for a couple of week and disappear also after the person is free from mental stress. The mouth ulcers can be prevented if proper dental hygiene is maintained. Proper care of the teeth and gums should be taken. The dentist should be visited regularly. Proper type of food should be eaten i.e. food which is rich in vitamin and protein should be consumed on a daily basis. Intake of fresh fruit, wholegrain bread, iron, potatoes, green vegetables and milk should be increased.  Too hot food and drinks should be avoided so that no damage is caused to the inner lining of the mouth. Treatment For Mouth Ulcers The mouth should be regularly rinsed with iced water to get relief from the ulcers. Washing the mouth prior to meals also helps to a larger extent. Sometimes painkillers can also be taken. Antibiotics are administered in case of severe mouth ulcers. But medicines should be given only on the recommendation of the doctor.  Intake of hot food and spicy food should be avoided as it might aggravate the situation. Rubbing the ulcers with hand should be avoided as it might spread the infection. The mouth ulcers are a result of minor internal injuries. These are caused due to accidental biting of the inner portion of the mouth. Rough toothbrushes are also responsible for the development of mouth ulcers. Sometimes they are the result of bacterial infection. Anti-bacterial mouthwash can be used to prevent the ulcer from spreading and it also gives temporary relief. Thanks