There are different reasons for a person to chew on their tongue; a common reason is attributed to stress, some more serious reasons are possibly due to hairy leukoplakia or even the human immunodeficiency virus commonly called HIV. Tongue chewing is not that uncommon and can be diagnosed by a dentist during a routine checkup.
Wounds that are white in color and have a slightly ridged appearance is how hairy leukoplakia looks in the mouth. One of the things that may cause the patient to have this condition is if they have HIV or any other type of immune compromising conditions. Since hairy leukoplakia is a mild condition, there is no treatment needed.
If the tongue biting is just caused by stress there are multiple ways a patient can try to stop this habit. A common method used by dentists to stop tongue biting is to have the patient wear a mouth guard for a period of time. Mouth guards are used for various other problems like teeth grinding or clinching of the jaw. The dentist may also suggest finding ways to reduce the stress causing factors in the patients life. Once the habit is broken, try to keep stress levels down so there is not a relapse.