Parents are often confused because there was no fall, cut, or obvious accident. However, blood blisters can form quietly during everyday activities.
Common causes include:
Pressure from tight shoes or socks
Extended walking or standing
Footwear that rubs in one specific spot
Jumping, running, or sports activity earlier in the day
Pinching of skin during movement
During sleep, swelling can increase slightly, making the blister more noticeable by morning. What felt like mild discomfort the night before may suddenly look severe in daylight.
Why It Can Be Painful and Affect Movement
A blood blister can be quite tender, especially on the sole of the foot where pressure is constant.
Pain may occur because:
Blood trapped under the skin creates pressure
Nerve endings in the foot are highly sensitive
Weight-bearing increases discomfort
Swelling limits natural movement
Children may refuse to walk or limp because putting pressure on the area hurts. This reaction is common and does not automatically mean something more serious is happening.
However, inability to move the foot at all, worsening pain, or rapid swelling should never be ignored.
What a Blood Blister Typically Looks Like
A blood blister may appear as:
A raised bubble under the skin
Dark red, maroon, or purple in color
Smooth or slightly firm to the touch
Tender or sore when pressed
The surrounding skin may look normal, or it may show mild swelling.
Most blood blisters heal naturally within one to two weeks if protected properly.
