Your hair structure is complex. Though there are different types of hair – straight, wavy, curly and coiled – every hair starts growing from a single follicle. The hair bulb is the base of every follicle, and it’s a cluster of cells that reproduce to make new hair cells. As a result, your hair grows longer. The hair that you see is called the hair shaft.
Each strand of hair is composed of three main layers: the medulla, cortex and cuticle.
The 3 layers of hair
The medulla. The medulla is the innermost layer of the hair; it’s soft and practically invisible. It’s the central column of the hair shaft and has a structure similar to a honeycomb as it consists of transparent cells and air spaces. The medulla is made of keratin, and it’s not present in every hair — only in large, thick hairs.
The cortex. The cortex is the middle layer of the hair — and the thickest making up 75% to 80% of hair’s volume. The cortex layer dictates the strength, color and texture of your hair. This layer of the hair is made from tiny fibers of keratin running parallel to each other.
The cuticle. The cuticle is the thin, outermost layer of your hair, and it is comprised of overlapping scales of about 10 layers. These scales are transparent allowing the hair color to show through. Like tiles of a roof, the cuticle layer protects the hair by keeping nutrients in.
If the scales of the cuticle are broken, it exposes the cortex allowing harmful environmental toxins and excess heat to get absorbed. As a result, the hair will look dull and rough. Loss of moisture from the hair can also lead to hair loss.
Hair care and hair loss
Given the different types of hair, there isn’t one best way to care for it. You should find a grooming and hair care routine that works for you. Supporting healthy hair growth from within should be part of that routine as well, especially if you’re starting to notice hair loss or hair thinning. Use high-quality hair care products, try essential oils for your hair and supplement your diet with vitamins to ensure your hair is getting all the nutrients it needs.