I have a blood blister on the lower area of my left breast (for a week)and another on my right shoulder blade(two days). I don t believe friction caused them as I wear very loose fitting cloths. BACKGROUND INFO: I m very fatigued, all recently suffered a head injury causing psychogenic movement disorder although I m back to my normal self. I just went to Scotland and had a few bites one left a red mark on my hand. My back is in constant pain in my upper back. I m an 18 year old girl and don t seem to be the healthiest, extremely skin sensitive (rash, sun, freckles) and am worried these blood blisters aren t just blisters.