"Toughness" means that the hair is strong, elastic and has no split ends.
This kind of elastic hair plays an important role in resisting external forces and keeping the shape and length of hair unchanged. Even if the hair is twisted, its good elasticity can still make the hair completely return to its original state without damage. Hair dyeing, too much sunlight and artificial ultraviolet rays will destroy the keratin structure of hair, thus affecting the elasticity of hair. Once the hair is injured, the toughness and elasticity will be greatly reduced, and it is easy to break and split.
The second criterion of hair health: moisturizing
"Moisturizing" means moistening, not greasy and static.
Regardless of the eastern and western races, the scalp has sebaceous glands, which are extremely rich in human sebaceous glands. The secretion of oil is beneficial to scalp skin care. Too many hair follicles are blocked, too few are easy to dry and dandruff, and moderate is ideal. Healthy hair retains about 10% moisture in a mild environment, and only absorbs about 15% moisture of its own weight even if it is completely wet. The injured hair loses water seriously when it is dry, so there are problems such as dryness, static electricity and flying hair.
The third criterion of hair health: softness
"Soft" means soft, smooth, easy to comb and not knotted.
Healthy hair feels like satin, soft but not astringent, smooth but not greasy, and easy to set. Injured hair is as dry as branches, easy to knot and difficult to set. If the hair scales are seriously damaged, we can roughly judge by the feeling of smooth hair. The specific method is to comb your hair, and whether it is easy to knot. Usually, the lack of hair scales will affect the surface smoothness of hair, resulting in increased friction when combing hair, which is not easy to comb and knot.
The fourth standard of hair health: bright
"Bright" means shiny, full of hair color and bright.
Healthy hair is shiny, showing sufficient nutrition and vitality, not dull, withered and brown. In fact, hair is made up of protein. protein contains many substances such as hydrogen, oxygen, phosphorus and iodine, trace elements such as calcium, iron, zinc, copper and cobalt, and many vitamins. Seaweed such as kelp and laver are rich in calcium, iron and iodine, which can enhance the secretion of thyroxine and greatly help the color of hair.
These are the standards of hair health. You can measure yourself according to the above standards, and you can also "diagnose" whether other people's hair is healthy.