Bad hair days don't discriminate. We've all been there; that place where our hair won't cooperate just the way we'd like. Or a new style that we're trying, doesn't turn out as we had hoped. While those sort of hair troubles are par for the course and cannot be avoided completely, there is an entirely other issue that sometimes plagues our lovely tresses. That flaky nuisance, known as dandruff, is not just unsightly and embarrassing, it's also annoying and even uncomfortable. The white flakes are produced by an overactive, unhealthy scalp. Da...