Smoking is the most common reason for a stained tongue. The heat and chemicals in tobacco cause the papilla (little projections) on your tongue to elongate. This creates a lot more surface area where stain from the tobacco and other foods and drinks can get caught. It usually ends up taking on a brownish black appearance on the top of your tongue. Occasionally you’ll get a yellow or greenish color as well. Scraping and brushing will help some but you won’t be able to rid yourself of it until you stop smoking and allow your tongue to heal.
Thrush is the overgrowth of a yeast known as candida albicans on your tongue. Thrush looks like a white covering on the top of your tongue that you can wipe off. It is usually the result of taking antibiotics or a weakened immune system. Check out our post on thrush for for more information on what you can do for it.
Foods and Drinks
The most common foods that cause a stained tongue are dark drinks like coffee and tea. Other types of food that have heavy amounts of food coloring tend to stain your tongue as well. Reducing how often you consume these foods or drinks and brushing your tongue consistently can help quite a bit here.
Allergies, low iron, and a dry mouth are all causes of glossitis (inflammation of your tongue). In these cases your tongue swells slightly, takes on a very smooth appearance, and generally turns a pale red color. Once you figure out what is causing it and treat it, it should go away.
Acid reflux can cause your tongue to take on a yellow tint. Treat the acid reflux with medications and diet changes and it should help.
Several B vitamin deficiencies can cause your tongue to take on a bright or dark red color as well as becoming very sore.