Blisters on both sides of the tongue may be caused by herpes simplex, lobular papillitis, traumatic hemorrhagic blisters and other diseases, as follows. 1. herpes simplex: herpes simplex virus infection caused by clusters of small blisters, blisters with thin walls that are easy to break, forming irregular vesicles. 2. Lobular papillitis: lobular papillae are located on both sides of the posterior part of the edge of the tongue, the papillae are red and swollen like blisters during inflammation, and patients may have pain or discomfort. 3. traumatic blood blisters: can be caused by eating too hot food or dry hard food, such as chewing careless or bad repair body edge trauma led to blood blisters on both sides of the tongue, may be accompanied by erosion or ulceration. There may be other causes of blisters on both sides of the tongue, it is recommended to go to the hospital in a timely manner, to clarify the cause of the disease and then targeted treatment.