Black tongue is a condition in which the tongue has a black appearance. The tongue could also have a brown or yellow discoloration. It is a condition that is not dangerous and usually goes away without medical attention. There can be other symptoms associated with black tongue, including a fuzzy or hairy appearance to the tongue and bad breath. There can also be a metallic or unusual taste associated with black tongue.

Physical Cause

The tongue is primarily composed of muscles. It is covered with a mucous membrane. The upper surface of the tongue has small bumps called papillae. Taste buds reside between the small bumps. When the papillae grow longer and do not properly shed, a black appearance develops, which is called black tongue. The changes in appearance to the tongue usually begin toward the back of the tongue and progresses forward toward the front of the tongue.

Oral Hygiene

Causes of Tongue Discoloration

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Poor oral hygiene can result in black tongue. The bacteria can grow between the papillae, giving the tongue a black appearance. For good oral hygiene, the American Dental Association (ADA) recommends brushing twice per day with an ADA-approved toothpaste, cleaning daily between the teeth, limiting snacks between meals and having regular dental visits. The ADA also recommends replacing your toothbrush every 3 to 4 months.

Antibiotic Use

Changes in the normal levels of yeast or bacteria in the mouth can occur after the use of certain antibiotics. These changes can cause black tongue.

Mouth Breathing

What Causes a White Coating on the Tongue?

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According to the Georgia Department of Community Health, breathing through the mouth can cause black tongue 1. Breathing through the mouth can allow bacteria to enter and grow in the papillae, giving it a black color.

Mouthwashes, Bismuth and Tobacco

The regular use of mouthwashes that contain peroxide or other oxidizing agents can cause black tongue. Also, mouthwashes that contain witch hazel, menthol or other astringents can cause black tongue. The oral use of medications that contain bismuth can cause black tongue. Heavy tobacco usage can cause black tongue, too. These causes change the chemistry in the tongue, which can result in substances that give the tongue a black appearance.