Hair Life Cycle

Hair on our scalp grows about 0.3 to 0.4 mm every day. Hair growth and shedding is random and not a seasonal thing for humans, unlike mammals. A random number of hair strands will fall out in one of the three hair growth stages, namely, Anagen, Catagen and Telogen.

On average, hair will last for two to six years before it falls off. The growth cycle of a hair begins with the anagen phase, which is followed by catagen and telogen stages. The growth and shedding process lasts an average of about three years.

Anagen Stage

The anagen phase lasts for several years and the average is 3 years. When the old hair falls out or is shed naturally, the bare area of the scalp allows room for the growth of a new strand of hair.

Many people who face difficulty growing their hair beyond a certain length may have a short Anagen phase. While others who have long hair may have a long active phase of hair growth. The hair on our arms, legs, eyebrows and eyelashes have a very short Anagen phase, nearly about 30 to 40 days. This explains why they are so much shorter than scalp hair.

Catagen Phase

Catagen is defined as the transition phase of the hair growth cycle, following the anagen phase. 

The catagen phase is the shortest phase of the hair growth cycle. Unlike the other two phases, it is not characterized by the production of new hair but by the involution or destruction of hair follicles.

The process of destruction and involution may take up to 3 months, after which a resting (telogen) period begins.

Catagen is the intermediary stage in the transition of the hair life cycle. The phase is a transitional phase transitioning from the anagen to the telogen stage. Catagen itself can be referred to as a period of transition.

The catagen stage begins when the hair follicle moves from the anagen stage of growth to the catagen state of growth and eventually telogen. 

Catagen is when the active growth cycle of the hair follicles becomes shorter and the inactive growth period becomes longer.

The catagen phase only lasts for two weeks.

During this phase, there is practically no inflammation on the scalp. This is when some people go bald as most people experience this phase during puberty or due to hormonal imbalances or stress, etc.

Telogen Phase

When you lose a lot of hair, it is normal for it to take around 3 months for the hair to fall out. During this time, the hair follicle is said to be in the telogen phase. Telogen means ‘to grow’; ‘germinate’ literally. The hair growth cycle begins with anagen (growth). 

In the telogen phase, the hair follicle is dormant and the hair strands are no longer actively growing. The average length of this phase is four months, although this can vary from two to six months. Normally, approximately 10% of all the hairs on the scalp are in this phase at any time. Eventually, the resting hairs fall out and new hairs take their place.

The telogen phase begins when the body starts entering into a resting state, which is known as the anagen catagen transition. During this time, hair follicles begin to enter a resting stage.

Follicles in this state produce little to no hair shafts and instead produce a small, club-shaped structure called telogen hair. Telogen hair is not shed but remains attached to the follicle for two to three months. Telogen hair is typically finer than normal hairs.

The telogen stage is also known as the resting stage, which represents about 10-15% of the hair growth life. This phase is a resting period during which the hair follicle is not active, it ceases to grow and stays in a dormant state. 

The transition between Anagen and Catagen takes place smoothly as the cycle moves up in a synchronized way. In case of a sudden disruption of this synchronization, it can disrupt normal hair growth resulting in Alopecia.

A short Telogen phase can also lead to a hair loss condition known as Telogen Effluvium.

Does more Stress lead to Hair Fall?

What are the factors affecting hair growth cycle? Well, as you might be aware that hair fall is a problem that many people suffer from. You may not be aware of it but reducing hair fall is very much possible. Following simple remedies can help you get better and better results. 

Hair fall is an issue that a large number of people are facing these days. Women in their 20s and 30s have been facing hair fall problems more severely. 

The reason behind most of your hair fall problems lies in your stressful lifestyle. Excessive stress is said to be one of the biggest hair fall causes. Stress affects your hair in two ways: 

• Imbalanced diet: Stresses affect your digestion system. The food that you intake gets metabolised slowly thus affecting the strength of your hair. Stress leads you to eat junk food, which doesn’t have the nutrients that your body requires for normal hair growth. With a lack of proper nutrients, the quality of your hair deteriorates causing it to break easily. 

• Increased oil production: When you are stressed, you produce more oil in your scalp which makes the roots of your hair greasy and moist.

Take Away

The natural hair growth cycle consists of three well-defined phases: Anagen, Catagen, and Telogen phase. It is called Anagen for the growth phase lasting 2-5 years, Catagen for the transitional phase lasting about 10-15 days, and Telogen for the resting phase lasting 3-4 months.