Blood blisters can look alarming, appearing as dark red, maroon, or purplish bubbles beneath the skin, often causing mild tenderness or discomfort.

They form when tiny blood vessels break under the skin while the top layer remains intact, trapping blood and creating a raised blister.

Most blood blisters occur on fingers, palms, toes, soles, or inside the mouth from sudden pressure, friction, biting, or repetitive activity.

A typical blister may feel tender or swollen, but in most cases it will heal on its own within one to two weeks without medical treatment.

It’s usually best not to pop a blister, as the skin protects against infection. Cold compresses, gentle cleaning, protective bandages, and avoiding pressure help support healing and reduce discomfort.

Although most blood blisters are minor, seek medical advice if they become very painful, show signs of infection, grow, or take longer than two weeks to heal. People with diabetes, circulation issues, or bleeding disorders should be especially cautious and consult a doctor if blisters are repeated or unexplained.