The frequency of severe complications is higher in elderly patients than in young patients. NSAIDs and low-dose aspirin are often prescribed for elderly patients. Physiological functions of the stomach such as acid secretion in elderly patients are also different from those in young patients. Hemorrhage and perforation can suddenly occur in elderly patients even though abdominal symptoms are mild. There is a tendency for the condition of such patients to deteriorate and long-term hospitalization is often required. Effective prevention measures are necessary since it is expected that cases of gastrointestinal injury caused by NSAIDs will continue to increase.