A dark bubble under your skin can stop you cold.
It may follow a pinched finger or a painful new shoe, but its sudden appearance can leave you wondering whether something is wrong. Most blood blisters are harmless, but understanding basic care and recognizing warning signs can help you decide what happens next when you spot that unusual disc…
A blood blister forms when small blood vessels break beneath intact skin, trapping blood in a raised red or purple pocket. Pinching, friction, and pressure are common triggers, especially on hands and feet.
Inside the mouth, accidental bites or dental irritation may be responsible. Most heal naturally within one to two weeks. Avoid popping them: the unbroken skin protects the tissue underneath. Gently clean skin blisters, cover them with a soft dressing, and reduce rubbing.
For discomfort, apply a cold pack wrapped in cloth for short periods; never place ice directly on skin. Seek medical advice if redness spreads, warmth or pain increases, pus appears, or you develop a fever.
Unexplained, recurring, or persistent blisters also deserve assessment, particularly inside the mouth. If you have diabetes, poor circulation, or reduced immunity, get advice promptly, especially for a foot blister.
Mouth swelling that affects breathing or swallowing requires urgent medical attention.
