What causes black tongue?

Oral hairy leukoplakia: A fungal infection that manifests as white patches on the sides of the tongue. Can turn black if hair-like projections emerge from the white patch.

Addison disease: A disorder in which the adrenal glands do not produce enough hormones.

Smoking: Smoking can cause a brown or black discoloration on the tongue.

Black hairy tongue: A condition that causes the tongue to appear dark and fuzzy due to the buildup of dead skin cells, bacteria and fungi.

Certain medications: Some antibiotics and other drugs, such as chemotherapy, can cause a black discoloration of the tongue.

Stains from food or drink: Eating certain foods or drinking beverages that contain dark pigments, such as coffee or tea, can cause the tongue to become discolored.

Poor oral hygiene: Insufficient oral care can lead to the buildup of bacteria and other material that can cause discoloration.

Iron deficiency anemia: Low levels of iron in the blood can result in a black discoloration of the tongue.