Dandruff is those tiny white or yellowish flakes that sometimes appear in someone's hair and fall onto their shoulders. It happens when the skin on your scalp sheds dead cells faster than normal, creating visible flakes instead of the microscopic shedding that happens naturally all the time.

Everyone's skin constantly replaces itself, but dandruff occurs when this process speeds up, often because the scalp is too dry, too oily, or irritated by certain hair products. It's extremely common and not a sign of poor hygiene. Some people get it occasionally, others deal with it regularly. Cold, dry winter air can make it worse, and some people's scalps are just more prone to it.

Dandruff can be embarrassing when you notice those white flakes on your dark sweater, but it's usually easy to manage with special shampoos. The condition is harmless, though it can make your scalp feel itchy. If you see someone with dandruff, remember it's just a minor skin quirk, not something they did wrong or failed to prevent.