The reasons for repeatedly biting your tongue include both conscious and unconscious behaviors influenced by several factors:

• Stress and Anxiety: Tongue biting can be a physical response to stress, anxiety, or emotional tension, often happening unconsciously as a coping mechanism. Stress leads to muscle tension in the jaw and face, increasing the chance of tongue biting during the day or night.
• Concentration: Some people bite their tongues as a subconscious habit while focusing hard on tasks or work, linked to facial muscle tension.
• Sleep Disorders: Conditions like sleep bruxism (teeth grinding) and sleep apnea can cause tongue biting during sleep. Relaxed mouth muscles or involuntary jaw movements during sleep can lead to accidental tongue bites, sometimes linked to nighttime seizures or facial muscle spasms.
• Oral Habits and Fixations: Some develop the habit from childhood or stress relief needs, leading to repetitive tongue chewing or biting.
• Dental Issues: Misaligned teeth or bite problems can cause accidental biting while chewing or speaking.
• Nutritional Deficiencies: Lack of nutrients like vitamin B12 can cause oral discomfort leading to tongue biting.

If tongue biting happens frequently or causes injury, it is advisable to consider stress management, dental evaluation (for bite or alignment issues), and possibly using mouthguards for protection during sleep. Medical advice is recommended if linked to sleep disorders, seizures, or unexplained frequent biting. Thus, repeated tongue biting often involves a combination of emotional stress, physical conditions, habits, and sometimes underlying medical or dental factors.