Dandruff is the result of excessive shedding of dead skin flakes from the scalp. There may be minor itching, but no redness or scabbing occurs. It usually gets worse during the fall and winter and improves in the summer. Since dandruff is a natural process, it cannot be eliminated and can only be controlled or managed. You may notice that your dandruff gets worse when you’re under elevated or sustained levels of stress and anxiety. Getting your dandruff under control is relatively simple. Use an antidandruff shampoo that contains coal tar, salicylic acid, pyrithione zinc, sulfur or selenium sulfide. Each of these ingredients has a unique way to reduce dandruff. The tar-based shampoos slow cell production, while salicylic acid-based shampoos promote the shedding of dead cells before they accumulate. Pyrithione zinc and selenium sulfide reduce cell turn over. Since the primary cause of dandruff is a fungus, a medical ingredient like pyrithione zinc can effectively kill this yeast. Clinical studies indicate that the use of a shampoo and conditioner with this key ingredient provides an improved antidandruff effect.