A dry scalp (asteatosis) is the result of a reduction in the hydrolipid content of the skin, which causes dandruff, dry hair and itchiness. We can identify three different scalp problems, according to the variation of the relation between the lack of water and oils.
When sweat glands do not function well, impeding an adequate flow of water to the skin, it will become dry and dehydrated.
An oil deficit can be identified in dry, alipidic skin, occurring when the sweat glands do not produce a sufficient amount of sebum.

In dry, dehydrated and alipidic skin, we can observe a lack of both water and lipids (sebum). This situation results in asteatosis. Asteatosis is caused by both sweat gland disorders and environmental factors (cold environments).
Personal hygiene practices that are excessively drying, the use of alkaline and anti-grease shampoos, vitamin deficiencies, reduced consumption of vitamin A and an excessive use of alkaline-reducing-oxidizing substances all cause skin dehydration.
Dry, thin and off-white flakes form in the presence of dry skin and dandruff, accompanied by scalp itchiness, without pain on the skin and risk of seborrheic dermatitis.

Useful trichological treatments for dry hair are composed of regenerating, hydrating and nourishing substances and hydrophilic, natural oils. On an external level, these substances must provide oils and water in sufficient quantities for nourishing the skin. Massaging the scalp is also useful, with the function of preventing the accumulation of toxins that make the skin hard and compress the capillaries, of producing capillary vasodilation, facilitating the arrival of nourishing substances (anabolism) and of stimulating sebum secretion (production of essential sebum) that is useful for fighting dry skin and hair.

Laser treatments are also useful, facilitating blood irrigation to the bulbs, and revitalizing the activity of the pilosebaceous apparatus and sebum production.