A deep vertical groove in the tongue may be suffering from furrowed tongue. Furrowed tongue is also known as scrotal tongue, fissured tongue or folded tongue and is often associated with maple tongue. The cause of furrowed tongue is unclear. Common possible causes include age, geography, genetics, ethnicity, and nutritional factors. Some infectious and systemic diseases may also cause furrowed tongue. The prevalence is low before the age of 10 years and increases with age from 10 to 60 years. The common symptom of furrowed tongue is the appearance of different forms of fissures on the dorsal surface of the tongue, which vary in size, number, shape and depth. Doctors will conduct blood test, tissue smear, histopathology, bacterial culture, oral pH test, salivary composition test, etc., and make a comprehensive diagnosis by combining the patient’s clinical manifestations and test results. Asymptomatic patients with furrowed tongue generally do not need treatment, patients with obvious symptoms can be symptomatic treatment through drugs, including vitamin B, glutamine, diazepam, fluconazole, itraconazole and so on. Patients with serious conditions, such as the pain of the median longitudinal groove fissure is intolerable, etc., can choose surgical treatment to restore the shape. When a vertical groove in the middle of the tongue is found to be very deep, you should consult a doctor for a clear diagnosis and treatment, so as not to delay the condition.