Patients with glossitis typically experience swelling of the tongue, which tends to become dark red. In some cases, the tongue may turn other colors. For example, patients whose glossitis results from pernicious anemia may see their tongue turn pale. Glossitis related to vitamin B deficiency tends to turn the tongue fiery red, and is also typically smooth.

Glossitis occasionally causes tenderness and soreness of the tongue. Patients may have difficulty chewing, swallowing or speaking.

Patients with a specific form of glossitis called geographic tongue experience irregularly shaped red, smooth, bald areas of lacking papillae interspersed with areas of normal tongue texture resulting in a map-like pattern. This pattern constantly changes and may continue for months, or may go away and then recur.

The cause of geographic tongue remains unknown, although factors that are believed to contribute include allergies, a woman's pregnancy or menstrual cycle, irritation from certain foods (e.g., hot or spicy foods, cheese), and the use of alcohol or tobacco. There is no cure for this condition and treatment is generally aimed at easing symptoms and reassuring the patient since the condition is benign. However, some patients with geographic tongue may experience burning pain or soreness of the tongue. They are urged to seek immediate medical attention if their tongue becomes severely swollen or if they have trouble breathing, speaking, chewing or swallowing.

Median rhomboid glossitis is another inflammatory condition of the tongue characterized by a diamond or oval shaped red lesion in the middle of the tongue. It is thought to be congenital and may be secondarily infected with the fungus Candida. Once diagnosis is made (which may involve a biopsy), no treatment is required.