Afraid to wear a black blouse? You're not alone -- sooner or later almost everyone experiences at least a little flaking, but that doesn't necessarily mean you have dandruff. There are several things that can cause flaking that, technically speaking, aren't dandruff.

• Buildup: Heavy conditioners and many styling products are made to stick to your hair and can prevent the natural shedding of skin. Use a clarifying shampoo to rid yourself of buildup, and be sure to rinse very thoroughly every time you wash and condition. Keep very oily or greasy products away from your scalp.
• Dry scalp: This is a pretty common occurrence, especially in winter. When you wash your hair, use a mild shampoo and give yourself a scalp massage to loosen flakes. Resist the temptation to overcondition, which can cause buildup, but give yourself an occasionaldeep conditioningif necessary.
• Sensitivity: Your scalp might be reacting to harsh ingredients in shampoo; try using a gentler product.

If none of these describes you, you might have "real" dandruff. No one knows exactly what causes dandruff, though the current theory is that it's a type of yeast growing out of control. Regardless, there are a number of over-the-counter shampoos available that can help. The most effective ingredients -- antimicrobials -- to look for are zinc pyridinethione, selenium sulfide, sulfur and ketoconazole (also available by prescription). If your hair is colored, don't use products with selenium sulfide or sulfur. Coal tar is another option; it's not an antimicrobial, but it does slow the growth of skin cells, which means fewer flakes.