Psoriasis turns your skin cells into Type A overachievers: They grow about five times faster than normal skin cells. And your body can't keep up. The old ones pile up instead of sloughing off, making thick, flaky, itchy patches.
Why do these cells go a little haywire? There's more going on under the surface of this skin disease.
Researchers think something sets off your immune system. The exact reason is a mystery. But it's likely a combination of genetics and triggers.