The tongue is a muscular organ, covered with a highly specialized mucosa on the upper side and a coating mucosa on the lower side. Physiological or pathological changes may occur on the mucosa of the tongue. Physiological changes include: geographic tongue, fissured tongue and lingual varicosities. Pathological changes include: coated tongue, tongue atrophy, teeth impressions on the tongue, oral lichen planus and lichenoid reaction, leukoplakia, fibromas, warts and papillomas, medial rhomboid glossitis, tongue ulcers, and oral cancer. It is important to distinguish between healthy and sick tissue so that an accurate diagnosis can be established and effective therapy administered. Physiological changes generally do not require therapy, whereas some pathological changes require monitoring and / or immediate therapy because of possible malignant transformations. A doctor of dental medicine plays a key role in the detection of oral and tongue diseases. Today, increasing importance is attached to early diagnosis, prevention and informing patients, in dealing with both physiological and pathological changes. Each visit to the dental clinic begins with an examination of the entire oral cavity and tongue. The examination is extremely short, painless, simple and inexpensive, and diagnosing malignancies in the early stages can save a patient's life.