Hello.
If you discontinue smoking, you may get the numbness on the tongue and the mouth area. Otherwise, you will have to look for vitamin deficiency aw a cause.
Do you have any other symptoms? Do you have migraine?
Regards
If it is only a portion of your tongue and lip on only one side, it is possibly a high cervical subluxation or a migraine symptom. For subluxation, see a Physical Therapist specialist in Manual Therapy, or a Chiropractor. For a migraine see your doctor about trying Maxalt or other medication to prevent or ease the pain syptoms. Do you have any other symptoms?