Diagnosis

Diagnosis of black hairy tongue is based on appearance and possible causes or contributing factors. It also includes eliminating other conditions that may cause a similar appearance to the tongue, such as:

• Normal variations in tongue color (pigment)
• Foods or medications that have stained the tongue
• Fungal or viral infections
• Oral lesions that occur on the tongue, such as oral hairy leukoplakia
• Blackened tongue (pseudo-black hairy tongue) from using products containing bismuth, such as Pepto-Bismol