Oral ulcers are formed inside the mouth or around it on the lips. Mostly there is mild inflammation or breach in the mucosa.  Instead of breach in the inner lining, there may be small sores or painful blisters.These oral lesions are painful. After eating, one has a sense of irritation or pain after eating in presence of ulcers. If severe, one may even have difficulty in eating.  Once oral ulcers are formed, they may persist due to superadded infections or inflammation. Left untreated, they can result in tooth decay and or rot.  A persistent or recurrent ulcer can also become malignant.Oral ulcers are a fairly common problem said to be prevalent in 15-45% of population. Most of the people do have 1 to 5 or 6 episodes of these ulcers every year.  But few persons have persistent ulcers depending on the underlying cause/causes.Minor physical injury is the most common cause for ulcers in the mouth. Loose tooth, very hot drinks, spicy food, foods with high acid content, alcohol, all these can cause trauma to tongue or inner portion of lips resulting in breaking of the delicate inner lining. Deficiency of vitamin B.complex also makes one more prone to develop ulcers in the mouth. Chronic constipation and indigestion leads to coating of the tongue, which can develop small bisters or ulcers.Tobacco smoking can lead to discoloration of the lips and also ulcers on lips and tongue. Chewing tobacco or any substance continuously causes irritation of the tongue and buccal mucosa and can result in ulcers. Certain infections also cause ulcers in the mouth. Touching of dry and cracked lips with unclean fingers is a source of infection. Kissing is yet another route through which infections of the mouth can be transmitted from one person to another leading to ulcers or sores in the mouth. More intimate is the kiss, more is the risk. Bacterial infections particularly those caused by streptococci, anaerobic bacteria, e.t.c., can cause oral ulcers. Viruses like herpes simplex, Epstein barr virus are also implicated in recurrent oral ulcers and or eruptions in mouth. Fungal infections like oral candidiasis or thrush also lead to ulceration in the mouth. Ulcers in the oral cavity are also part of manifestation of some sexually transmitted diseases like syphilis.Since the mucosa (inner lining) of the mouth is in continuity with that of the throat, oral   ulcers can become a source of infections of the throat and even lungs. Via the blood stream, these infections can spread anywhere in the body causing serious infections.Immune suppressed people, like those suffering from HIV/AIDS or kidney failure are more prone to develop ulcers in the mouth due to infections. If one has suffered from oral ulcers, repeatedly, he or she should try to get the underlying cause identified and treated. For example, a loose tooth needs to be fixed or extracted. One should avoid taking very spicy food and hot beverages in excess, if he is prone to recurrent oral ulcers. Taking fresh green vegetables, fruits, nuts, whole grains and cereals helps the body get adequate nutrition and prevents oral ulcers. Drinking adequate amounts of water with high fiber   diet prevents constipation, ensures good digestion and also prevents oral ulcers.Alcohol and tobacco have multiple health hazards and should be avoided.While getting intimate with another person, an individual should ensure that he and his partner both are hygienically clean and do not suffer from any disease. This will   avoid development of many kinds of diseases including oral ulcers.In case of ulcers due to infections, the infection should be treated adequately with sufficient dose of antibiotics.Soothing ointments are available to apply over the ulcers to reduce pain. Anti-infective ointments are also used to cure the ulcer if it is infectious in origin.Supplements of vitamin B.complex are also useful in this regard.Dr. Rachna Pande is a Specialist (Internal medicine-Ruhengeri Hospital)