This document discusses dandruff, its causes, and treatments. Dandruff is caused by dry skin, irritated oily skin, not shampooing often enough, other skin conditions like eczema or psoriasis, a yeast-like fungus, or sensitivity to hair products. Common treatments include antifungals like ketoconazole and zinc pyrithione, coal tar, selenium sulfide, salicylic acid, steroids, and home remedies using tea tree oil, white vinegar, aloe vera, or olive oil. A case study found the highest rates of dandruff occurred in people aged 20-23, in winter, and those with oily skin.