How does a cut turn into a scab?

A cut becomes a scab because your blood quickly seals the opening. Platelets gather at the torn spot, a protein called fibrin makes a strong net, and the sticky clot dries in the air. That dry cover protects the gap while new skin forms.

The neat part is how quickly the job changes. White blood cells clean away germs, fresh vessels bring supplies, and skin cells creep inward from the edges. When the repair is ready, the old cover loosens and often slips away during washing or play.