What does your hair mean to you? Perhaps your most powerful and beautiful asset! Hair and beauty have a deep connection. Hair is one of the defining characteristics of women and men. Bad hair means a bad day. For some people, their hair is a form of personal expression. You might have noticed that on the day you have beautiful hair, you feel very confident. You naturally feel like I can conquer the world, because my hair is shiny, flowing smoothly, and looking amazing today! Healthy hair boosts confidence while bad hair actually spoils mood and enthusiasm. In this article, I am going to discuss all things about hair, what foods and factors affect your hair positively or negatively, and what are the solutions. But first, let’s see what hair is actually made of and how does it work?
Structure of Hair
Hair is made of keratin, which is a tough protein. Hair follicles grow from follicles found in the dermis layer of the skin; These follicles are called hair follicles, in simple terms, the part of the hair under the skin is called the hair follicle.
Hair Shaft: The part of the hair that is visible above your scalp is called the hair shaft. The hair shaft is made up of three layers: the cuticle, cortex, and medulla.
Cuticle: The cuticle is the outermost protective layer of the hair that consists of cells like fish scales (facing down) that overlap. These cells protect the cortex, the inner structure of the hair, from damage. It also regulates the moisture content of the hair fiber. The cuticle gives your hair shine and protects the inner layers from damage. However, excessive heat, chemical over-processing, and weather changes can damage the protective cuticle layer of the hair, affecting the integrity of the hair.
Cortex: The middle layer called the cortex is the main component of the hair. It consists of long keratin chains that provide bulkiness, strength, and elasticity to the hair. The health of your cortex depends mainly on how well the cuticle is protecting it.
The cortex also contains a pigment called melanin. Melanin is the pigment responsible for giving hair its natural color. Hair coloring, relaxing, thermal styling, and other aggressive treatments cause temporary or permanent changes in the cortex layer.
Cause of different hair colors
Two types of melanin are found in the cortex layer of hair:
Eumelanin is responsible for black and brown hair color.
Pheomelanin is responsible for blonde, red, and yellow hair color.
Grey or white hair is caused by the absence of melanin pigment in the cortex layer, which can be due to age or other factors.
Medulla: The innermost layer of the hair shaft, the medulla is made up of an amorphous and round cell. This layer is normally absent, especially in naturally blonde and fine hair and is usually present in thick, coarse, and dark hair.
This was all about the hair shaft, the part of the hair that is visible above your scalp. Now let’s look at what happens beneath the skin.
The intense biochemical and metabolic activity that develops beneath the epidermis is responsible for the development and growth of hair.
Hair bulb: The hair bulb contains stem cells that divide and form new hair follicles that form the hair shaft. The cone-shaped dermal papillae in the hair bulb contain a blood supply and nerves that nourish the cells and deliver nutrients to the hair.
Sebaceous glands: The sebaceous glands or oil glands attached to hair follicles release an oily or waxy secretion called sebum that lubricates and waterproofs hair. Sebum gives your hair a natural shine and protects it from bacteria. Thick hair has a greater number of sebaceous glands.
Hair growth cycle
Hair growth rates vary among different people; it depends on age, hair type, and hair health. Hair grows about half an inch (1.25 cm) per month on average; that means about 6 inches of hair per year. Every hair can be in a different stage of the growth cycle at any given time. Let’s see what these phases are and how long they last.1. Anagen (Growth Phase) Duration: 2-3 years (maximum 7 years)
Anagen is the active growth phase of hair follicles, during which the cells in the hair root divide rapidly, forming new hair. Normally 90-95% of hair follicles are in the anagen phase. Hair remains in this growth phase for two to a maximum of seven years.
2. Catagen (Transition or Regression Phase) 2-3 weeks (about 10 days)
Catagen is a short transition phase. It signals the end of the anagen phase, during which growth stops and hair follicles shrink, the outer root sheath attaches to the hair root and separates from the dermal papilla. This forms a bulge at the end, known as a club hair. The catagen phase lasts for about 2-3 weeks and about 1-2% of all hairs are in the catagen phase.
3. Telogen (resting phase) 2-3 months (about 100 days)
The telogen phase is the resting phase during which the hair follicle is in a completely resting state, and the end product of the hair follicle, the club hair, is fully formed. The club hair is a dead, completely keratinized hair, and if you pull out a hair in the telogen phase, it will show a solid, dry, white bulge at the root. This phase lasts for about 100 days, and about 10-14% of hairs are in the telogen phase at any given time.
4. Exogen (shedding phase)
This phase is characterized by the shedding of club hairs from the scalp resulting in hair loss. 100-150 hairs fall out every day in the exogen phase. Anything that disrupts the hair growth cycle, like bleaching, coloring, excessive heat, can cause more hair to enter the telogen phase, then in a few months the hair enters the exogen phase, causing more hair to fall out.
