Tricología

A specialty, not a trend

The trichologist studies hair and scalp from dermatology. The work starts with observation: density, shaft thickness, condition of the follicle, state of the skin underneath. That reading is what tells you where a head of hair stands.

Trichology does not work on the hair that has already grown out, but on the follicle, the living structure that produces it. That distinction explains why changes show up weeks or months apart, and not from one day to the next.

The scalp is skin too

It is easy to forget, but the scalp is skin: it has its own barrier, its microbiota and its glands. When that skin is not in good condition, the hair growing from it shows it.

That is why trichology starts there and not at the lengths: the ground conditions what comes out of it.

The hair you see is dead tissue. Everything that decides its condition happens under the skin.

What you see and what you do not

A scalp has on the order of a hundred thousand follicles, and from each one grows a hair with two clearly different parts. The root, held in the follicle under the skin, where the hair forms and feeds. And the shaft, the visible part, which no longer has biological activity.

The cuticle is the outer layer, made of overlapping scales like the tiles on a roof. When they are closed and aligned, the surface is smooth and reflects light. When they lift, the fiber loses evenness and tangles.

The cortex is the middle layer and the thickest one. It provides strength, elasticity and color, because that is where melanin sits.

The medulla is the central channel. It is not present in every hair and is more common in thick ones.

This structure explains why caring for hair is, above all, caring for the cuticle: it is the barrier that protects what is inside.

Hair follows a cycle

Anagen The growth phase. It lasts between two and seven years depending on the person, it is by far the longest and it sets the maximum length a hair can reach. In a healthy scalp, most follicles are in it.

Catagen The transition phase. It lasts about two or three weeks. The follicle stops production and retracts.

Telogen The resting phase. It goes on for about two or three months. The hair stays in place without growing until it sheds and the follicle starts a new cycle.

Hair in numbers

100,000 Follicles, roughly, on one scalp

2 to 7 years How long the growth phase of a single hair can last

50 to 100 Hairs shed per day under normal conditions

Not everything happens on your head

Genetics Sets thickness, shape, density and much of how the follicle behaves.

Hormones Hormonal changes alter the hair cycle, and they show up in the hair weeks after the change that causes them.

Age Over time the follicle produces finer fiber and the growth phase shortens.

Diet Hair is one of the last tissues to receive nutrients. When intake is tight, the body prioritizes other functions.

Rest and stress Sustained stress influences the cycle, and the effect shows months after the episode that causes it.

External damage Heat, bleaching, dyes, chlorine, salt and friction act on the cuticle, the layer that does not regenerate.

When to see a professional

Sudden, heavy shedding, or shedding that does not ease off over several months.
Loss of density in one specific area.
Itching, flaking, redness or pain on the scalp.
Abrupt changes in hair texture or thickness.
Hair that breaks easily with no apparent cause.

What trichology is