These are the consequences of sleeping with the

This appears to be a large, tense, dark-colored blister filled with blood (often called a blood blister or hemorrhagic blister) on the ball of the foot.

Possible causes include:

• Repeated friction or pressure from walking, running, tight shoes, or sports.
• Trauma or injury, such as stepping on something hard or a direct impact.
• Less commonly, burns, severe skin irritation, or certain medical conditions affecting blood vessels or clotting.

The dark gray/black color suggests blood has collected under the skin. However, because it is quite large and unusually dark, it’s important to have it examined by a healthcare professional, especially if:

• It appeared without a clear injury.
• It is very painful.
• It is growing in size.
• The surrounding skin becomes red, warm, or starts draining pus.
• You have diabetes or circulation problems.