Blisters on the lips and tongue, accompanied by a sore throat may be caused by primary herpetic gingivostomatitis or herpes zoster, as follows. 1. Primary herpetic gingivostomatitis: caused by herpes simplex virus infection, the oral cavity and lips and perioral skin can occur in clusters of small blisters, the size of a pinhead, the blister wall is thin and easy to break, can form irregular vesicles. It can cause sore throat. 2. Herpes zoster: varicella-herpes zoster virus infection caused by lesions in the skin and mucous membranes, unilateral, band-like distribution, herpes dense clusters, ulceration to form a larger vesicle, can be accompanied by sore throat. Lips and tongue blisters, accompanied by a sore throat may have other causes, it is recommended to go to the hospital in time, clear cause for targeted treatment.