Hair
Hair Disorder: Know Where is the Problem
It is not uncommon for hair texture to be altered as a result of injury to the scalp: examples include curly hair becoming straight or straight hair becoming curly. As the injury heals, normal hair texture often eventually returns as new hair is made.
The hair follicle can only respond in a limited number of ways to genetic programming, disease, or injury. Either follicles may be destroyed, the hair cycle altered, the quality of the hair changed, or a combination of these may occur. A typical alteration of the hair cycle occurs in common baldness (androgenetic alopecia), where the follicle progressively has shorter and shorter growth phases resulting ultimately in hairs so fine that they are hardly visible. In cases of malnutrition, pigment may be diminished, the calibre of hair may decrease and hair may be shed, not being replaced until nutritional status has improved. In certain genetic diseases, the structural integrity of the fibres may be so poor that hairs will break off at the surface of the skin, leaving little more than stubble behind.
Knowing whether a hair problem is due to a hair cycle abnormality or a structural problem with the hair fibres is very important in determining the nature of hair disorders.