Commute 45 to 59 min. 7.20%. Commute greater than 60 min.
1 Oral Ulcers: Usually, an ulcer is referred to as an open wound which is formed inside the mouth and this occurs due to the invasion of micro organisms. 2  Sometimes, blood blisters are caused due to the skin infections caused as a side effect of medications. 3  Ulcers are of two types they are: Canker sores and Cold sores.
Piercing: Lip piercing and tongue piercing may also lead to formation of blood blisters in mouth. This may be due to an injury during piercing of an infection on the piercing that occurs later after piercing. A blood blister in the middle of tongue after piercing.