<s>[INST] i have a blood blister on the rigth side of my tongue what is the cause of this,i am 40 year old woman, my height is 5 feet 2 and haft, my weight is 9 stone 9, i have asthma,ibs,hp,mygrins,mother died of cancer two and havf years ago ,dad had kindy cancer last year in remsion. [/INST] Hello and thanks for consulting Chat Doctor.I have read your query. Blood blister or Hemorrhagic blister on tongue can be due to trauma to the tongue. Angina bulls hemorrhagic (ABH) is a condition that is characterized by the sudden appearance of a blood filled blister on the tongue and oral mucosa in the absence of an identifiable cause or systemic disorder, commonly seen in middle and elderly people.I would suggest you to visit an oral and dental surgeon to find out the exact diagnosis. If it's a normal blister then he would Chat Doctor. Hope this answers your query. Take disregards </s>