Hair Anatomy & Physiology
Your hair consists of three layers - cuticle, cortex, and medulla. Its overall health depends on your daily hair care regimen as well as the hair’s physiological traits.
When a healthy hair strand is observed under a microscope, the three layers lay smoothly over each other. The cortex and medulla are protected by a thick and undamaged layer of cuticle. This is why healthy hair looks shiny and dense with color.
If you have a normal scalp, your hair tends to have the characteristics of normal hair.
- Moderate amount of moisture
- Naturally conditioned, better volume and sheen
- Healthy water inlet and outlet
- Ideal sebum production
- Moderate resistance to breakage and damage
An oily scalp is characterized by overactive sebaceous glands.
- Excessive sebum production
- Greasy hair
- Low porosity & ability to lose or absorb moisture
- Very well-conditioned hair & high resistance to damage
Dry scalp is accompanied by dry hair and its defining characteristic is its low ability to retain moisture.
- Frizzy and dull hair
- High porosity and moisture loss
- Low sebum production
- Low resistance to breakage and damage
Oily scalp With Dandruff
Dandruff is a common scalp issue caused by excessive production of skin cells in the scalp. Multiple factors can contribute to it, including:
- Malassezia furfur, a naturally-occurring yeast in the scalp.
Dry Scalp With Dandruff
Dandruff is a common scalp issue caused by excessive production of skin cells in the scalp.
- White flakes caused due to a lack of moisturization
- Dandruff tends to fall off the head
To understand hair damage, you must first understand the anatomy of healthy hair. When the hair is healthy, its cuticular layer lies flat on the cortex (core of the hair). Due to this, the hair looks shiny and smooth.
When a hair strand is damaged, its cuticular layer is destroyed which leaves the cortex vulnerable to breakage, dryness, dullness, and frizz.
Level 1 damage in hair is caused when cuticles are uneven instead of being flat. Cuticular cells may be raised or broken with Level 1 damage. But the damage, in this case, is not intense enough to fully expose the hair's internal cortex.
It can be caused by UV exposure, pollution, frequent hair washing, etc.
Symptoms of Level 1 Hair Damage are:
- Slight dryness in hair
- Slightly dull hair
- Thinner ends
- Moderate breakage
Level 2 Hair damage is severe with the cuticular layer beginning to break down. A larger number of cuticular layers are jagged. This leaves the hair fiber unprotected in some areas; cortex can be fully exposed at certain places in the hair strand.
Level 2 damage can be caused by subjecting hair to chemical treatments such as coloring and bleaching.
Symptoms of Level 2 Hair Damage
- Coarse hair texture
- Uneven color balance and dullness
- Split ends
At the highest level of hair damage that is level 3, the cuticular layer may be completely destroyed throughout the hair, leaving the cortex majorly vulnerable.
Level 3 damage can be caused by heat application on the hair. Heat treatments such as straightening, curling, styling, etc can cause severe damage to hair.
Symptoms of Level 3 Hair Damage
- Very coarse hair texture
- Shineless and dull hair
- Faded color
- Split ends throughout hair strands