Hair revitalisation & fortification
Hair Science - Dermatologists & Aestheticians
Hair science, also known as trichology, is a multidisciplinary field that focuses on the scientific study of hair and its related structures. It encompasses various aspects of hair growth, structure, function, and health. Hair science draws upon knowledge from biology, biochemistry, physiology, dermatology, genetics, and other relevant disciplines to understand the complexities of hair and its interactions with the human body.
Hair science is one of the most captivating topics as hair disorders are numerous. Hair science involves the collaboration of different professionals who specialize in hair and scalp health. Among them, dermatologists and aestheticians play distinct roles:
Dermatologists: Dermatologists are medical doctors who specialise in diagnosing and treating conditions related to the skin, hair, and nails. They undergo extensive medical training and are board-certified in dermatology. When it comes to hair science, dermatologists have a comprehensive understanding of the physiology of the skin and hair, making them well-equipped to diagnose and treat various hair and scalp disorders.
Aestheticians (Cosmetologists): Aestheticians, also known as cosmetologists, are trained skincare specialists who focus on improving the appearance and health of the skin, including the scalp. They receive specialised education and certification in various products and treatments, along with skin & scalp techniques.
The Hair Growth Cycle
The hair growth cycle, also known as the hair growth phases, consists of three main stages that hair follicles go through repeatedly throughout a person’s life. Each hair strand on the scalp is at a different stage of the cycle at any given time. Understanding this cycle is essential to comprehend hair growth patterns and the effects of various treatments on the hair. The three phases of the hair growth cycle are:
Anagen Phase (Active Growth Phase): Anagen is the active growth stage of hair. During the anagen stage the hair contains its highest amount of melanin. This stage lasts between 2-7 years. Approximately 85% of all hairs are in this growing phase at any one time. Hair growth is very active during this period, and division of cells is rapid. At any given time, approximately 85% to 90% of the hairs on the scalp are in the anagen phase. This is why most of the hair on the scalp appears to be growing and actively visible.
Catagen Phase (Transition Phase): At the end of the anagen phase the hairs enters into a catagen phase which lasts about one or two weeks, during the catagen phase the hair follicle shrinks to about 1/6 of the normal length. The lower part is destroyed, and the dermal papilla breaks away to rest below. This phase signals the end of active hair growth as it cuts individual hairs off from blood supply and from the cells that can produce new hair. Approximately 3% of all hairs are in this stage at any time. Only about 1% to 2% of the hairs on the scalp are in the catagen phase at any given time. This phase is relatively brief compared to the other stages of the hair growth cycle.
Telogen Phase (Resting Phase): The telogen phase is the third stage of the natural hair growth cycle. It is known as the resting phase. It follows the catagen phase and normally lasts about 5-6 weeks. During this time the hair remains dormant for the next hair cycle, it does not grow but stays attached to the follicle while the dermal papilla stays in a resting phase below. Approximately 10 – 15 percent of all hairs are in this phase at any one time. This phase lasts for around 100 days. Approximately 10% to 15% of the hairs on the scalp are in the telogen phase at any given time. This phase is responsible for normal hair shedding, which is a natural process in which the old hair is released, and new hair takes its place.
Exogen Phase (Shedding Phase: At the end of the telogen phase the hair follicle re-enters the exogen phase. The dermal papilla and the base of the follicle join again, and a new hair begins to form. If the old hair has not already been shed the new hair pushes the old one out and the growth cycle starts all over again.
Each hair follicle is independent and goes through the growth cycle at different times, otherwise all your hair would fall out at once. Instead, you only shed a certain number of hairs a day – from 50 – 150 on an average healthy head of hair.
It’s essential to note that various factors can influence the duration of each phase, such as genetics, age, hormonal changes, and overall health. For example, hormonal fluctuations during pregnancy or certain medical conditions can affect the hair growth cycle and lead to temporary or chronic hair loss. Additionally, hair follicles on different parts of the body may have varying growth cycles, resulting in differences in hair length and texture.