Burns or frostbite (less common)
It typically appears as a dark red, purple, or black bubble and may be tender—but not usually severely painful or disabling.
✅ Normal blood blister:
Develops after activity (not overnight with no cause)
Located on weight-bearing areas (heel, ball of foot, toes)
Pain is mild to moderate
She can still walk (with discomfort)
⚠️ Red Flags: When It’s NOT Just a Blood Blister
