Structure of Hair: Human hair is made up of a protein called keratin, the same protein found in nails and the outer layer of the skin.

It consists of three main layers: the cuticle, cortex, and medulla.

Cuticle: The outermost layer composed of overlapping scales that protect the inner layers of the hair.

Cortex: This middle layer provides the hair’s strength, color, and texture. It contains melanin, which determines the hair’s color. 

Medulla: The innermost layer, which is sometimes absent in fine or light-colored hair.

Hair Growth Cycle: Human hair goes through a regular growth cycle that includes three phases:

Anagen (Growth Phase): Hair actively grows during this phase, lasting for several years. The hair shaft is produced in the hair follicle and pushes up through the scalp.

Catagen (Transitional Phase): This phase is relatively short, lasting only a few weeks. Hair growth stops, and the hair follicle starts to shrink.

Telogen (Resting Phase): The hair follicle remains inactive during this phase, which lasts a few months. Eventually, the old hair is shed, and a new cycle begins.

Hair Types: Humans have various hair types based on ethnicities and genetic factors.

The main hair types are:

• straight
• wavy
• Curly
• coyly

These differences result from the shape of the hair follicle and the angle at which the hair grows from the scalp.

Hair Colour: Hair color is determined by the type and amount of melanin present in the cortex of the hair shaft.

Melanin is a pigment produced by specialized cells called melanocytes.

The two main types of melanin are eumelanin (responsible for black and brown hair) and pheomelanin (responsible for red and blonde hair).

The combination of these pigments results in the wide range of hair colors seen in humans.

Hair Growth and Maintenance: The rate of hair growth varies among individuals, but on average, hair grows about 1.25 centimetres (0.5 inches) per month.

 Proper hair care, including regular washing, conditioning, and avoiding excessive heat or chemical treatments, can help maintain healthy hair.

DHT stands for dihydrotestosterone, and it is an androgen hormone derived from testosterone. DHT plays a significant role in the development of male characteristics during puberty, but it can also have negative effects on hair growth.

Hair loss related to DHT is known as androgenetic alopecia, male pattern baldness, or female pattern hair loss, depending on the gender affected. Here’s how it works:

Testosterone is converted into DHT: Testosterone is naturally present in both men and women, and it plays a role in various bodily functions.

An enzyme called 5-alpha-reductase converts testosterone into DHT, which is a more potent androgen.

DHT affects hair follicles: DHT attaches to hair follicles, particularly those on the scalp, and over time, it can cause them to shrink. This process is known as “miniaturization” of hair follicles. As the follicles shrink, the hair becomes finer and shorter, eventually leading to hair thinning and loss.

Genetic predisposition: The extent to which DHT affects hair follicles is largely influenced by genetics. People with a family history of androgenetic alopecia are more likely to experience hair loss due to DHT.

It’s important to note that not everyone will experience significant hair loss due to DHT. Some individuals may have a higher sensitivity to the hormone, while others may not experience any noticeable effects on their hair.

Hair transplant surgery involves taking hair follicles from one area of the body (known as the donor area) and transplanting them to another area that is experiencing hair loss or thinning (known as the recipient area).

Traditionally, the most common donor area for hair transplant procedures is the back of the scalp, as the hair there is less likely to be affected by male pattern baldness or other forms of hair loss. However, in cases where the scalp’s donor area does not provide sufficient hair follicles, or if the patient prefers not to use scalp hair, hair can be taken from other parts of the body.

Beard and chest hair are two common alternative donor areas for hair transplantation

In hair transplantation, the procedure called “Follicular Unit Extraction” (FUE) involves extracting hair from the backside of the scalp, which is known as the “permanent hair zone.” This region is less affected by the hormone dihydrotestosterone (DHT), responsible for hair loss in individuals with androgenetic alopecia (pattern baldness). The hair follicles in this area are more resistant to DHT and have a lower likelihood of falling out, making them the preferred choice for transplantation to areas experiencing hair loss.