A healthy normal hair is stronger than copper wire of the same crossection. Weakened hair is not as robust and can have all kinds of internal anomalies or defects in the formation of the hair shaft. Such hair are normally more weak and thin in comparison to helathy hair and they break easily. Sometimes these hairs diplay typical characteristics of one or another kind of illness, such as looking like an abruptly twisted spirals or glass fibers (pili torti), a spindly hair with an alternating thickening and thinning shaft, and sometimes hair grows in different directions and makes it impossible to set them into any hair style, etc. The most common defects in the hair shaft structure are congenital or may occur as a complication after some diseases or infections. Degenerative processes of scalp hair have been extensively studied using different microscopic studies and methods and this helped to determine in detail an occuring changes in the internal hair structure from the rooth to the tip as well as closely follow up on a cuticle scaling at the very same hair tip all way down to hair inner medulla layer. Nutrition has a huge impact on preserving the quality of hair. Deviations in hair health can occur due to shortage or lack of protein food due to various inappropriate diets, only vegetarian food, etc. The basis of the hair shaft structure is made up of the aminoacids, which are the main sources of proteins, some aminoacids are indispensable, therefore, limited food products, vegetables only for example, stimulate aminoacid deficiency, which leads to a shortage of building materials for the hair shaft structure. Shortage or lack of vitamins and trace elements also contributes to the weakening and deterioration of the hair shaft structure, as these vitamins and trace elements are the components of the structural frame of the hair and are involved in the processes of metabolism. Abnormalities of hair shaft conditionally divided into those that lead to hair fragility defects and those that lead to the hair formation defects.