Blisters commonly happen on your heels, toes, or other ... BLISTERS FORM UNDER the epidermis (the skin’s top layer) as a sac filled with clear liquid or blood, according to the Cleveland Clinic.

Subungual melanoma describes a form of malignancy that develops in the cells under the fingernail or toenail ... melanoma appears similar to a blood blister or a bruise that forms under the ...