Dandruff flakes are actually dead skin cells that naturally fall off the scalp — more so if you scratch. Many people think that a dry scalp is synonymous with dandruff, but either a dry scalp or an overly oily scalp can cause excess cells to clump and fall off, forming dandruff flakes. A number of skin conditions and other causes can make your scalp flaky. Some factors that can increase the risk of dandruff include: 1  Heredity. 2  Hormonal changes, like puberty. 3  Excess alcohol consumption. 4  Eating high-sugar, spicy, or high-salt foods. 5  Lack of nutrients like fatty acids and vitamin B. 6  Weather changes.