The black color of the tongue is usually a problem mainly due to poor oral hygiene, usual diet structure and reduced saliva production. There is no connection with early stage of stomach cancer. The black tongue is mainly formed by the excessive accumulation of oral exfoliated cells on the surface of the tongue. If you don’t brush and rinse your mouth frequently, dead skin cells will accumulate on your tongue more easily and the tongue will become black. Some oral diseases can lead to a decrease in saliva secretion, and some exfoliated cells on the surface of the tongue cannot be washed away by saliva, which can easily cause the tongue to become black. When normal people eat, mainly solid food, these solid foods can cause friction on the surface of the tongue, helping to remove the shedding cells on the surface of the tongue, the tongue can maintain a normal red state. Some people, for various reasons, eat more liquid food, which cannot cause friction on the surface of the tongue, so they tend to have a darkened tongue. Darkening of the tongue is actually a multi-factor result, mainly caused by the shedding cells of the mouth and tongue that cannot be removed and accumulated for a long time. It is not greatly related to whether it is early stage of gastric cancer or not. Early stage of gastric cancer can show some symptoms such as acid reflux, belching, burning sensation behind the sternum and so on. Generally, there are no specific symptoms in early stage of stomach cancer, and it is mainly detected through gastroscopy and gastroscopic biopsy. Early stage of stomach cancer cannot be judged by the appearance of the tongue. If you suspect that you have symptoms of gastric cancer, the best examination method is gastroscopy.