Hair loss is a type of skin disease, and the common types of hair loss are mainly divided into androgenic alopecia, alopecia areata, psychogenic alopecia, genetic alopecia, etc. 95% of the hair loss belongs to androgenic alopecia.
The pathogenesis of this disease involves genetic factors, androgenic effects, and environmental factors such as mental stress and unhealthy lifestyle habits. Androgens play a decisive role in the pathogenesis of androgenic alopecia, particularly in the conversion of testosterone to dihydrotestosterone by 5 α - reductase. Dihydrotestosterone binds to androgen receptors, leading to hair follicle atrophy and hair loss.
Skin photoaging is the damage caused by prolonged exposure to sunlight on the skin, resulting from the combined effects of natural aging and ultraviolet radiation. Manifesting as rough, thickened, and dry exposed areas of the skin, sagging skin, deepening and thickening wrinkles, excessive pigmentation or capillary dilation in the local area. Photoaging is more common in the elderly, with males experiencing it more frequently than females. It is more likely to occur on the face, neck, chest, back, and upper limbs and forearms.
