Run a comb through your hair and you might find a few hairs left behind in the teeth. If you see this happen every day, you might start to wonder if it’s normal that your hair is constantly falling out. A healthy scalp can expect to shed 50-100 hair strands on a daily basis.
Shedding hair is absolutely routine and just part of a hair’s standard growth cycle. Hair grows in stages, with a long stretch of active growth followed by a period of transition and then a period of dormancy. This repeats throughout a hair follicle’s life, with each one independently growing at different stages.
The hair follicle is actually a mini-organ with its own biological clock that, when out of balance or attacked in any way, can disrupt hair production. The follicle is nourished by the blood vessels and, when they’re clogged or when circulation is compromised in any way, hair won’t be able to grow.
To better understand how your hair grows – and what causes it to fall out – let’s examine what happens during each of the three phases.
The Anagen Phase
The longest phase of the growth process, this stage typically lasts between two to six years. The follicle is active and producing new cells resulting in hair growth at a rate of approximately ¼ of an inch per month. Each follicle’s Anagen phase is on its own clock. Since the period of active growth varies from person to person, individuals with a long Anagen phase can grow their hair much longer than those with shorter Anagen cycles.
The Catagen Phase
This transition cycle marks the end of active growth, preparing the follicle to separate from the hair. The hair bulb at the bottom of the follicle detaches from the blood supply and moves upwards. The follicle itself shrinks rapidly to encourage this upward push. The dermal papilla detaches from the follicle’s base, but does not travel up. Catagen is the shortest phase of the growth cycle, lasting only about two to four weeks.
The Telogen phase
The follicle rests and prepares for another round of the Anagen period. This dormant phase typically lasts between three to five months. The hair is matured and no longer has access to the blood supply because there is no longer a need to grow. Towards the end of this phase, a new hair follicle begins to form over top of the old, shrunken one.
Why Hair Loss Occurs
Our hormonal changes gradually impede hair growth by stifling the follicles ability to produce hair. The most important structure of a hair follicle is at the very base and called the dermal papilla. It is responsible for deriving nutrients for hair follicle growth and the cells of the dermal papilla divide and differentiates to form a new hair follicle.
Hair growth is a chemical process governed by hormones and the rate of cell division. People with a genetic predisposition for hair loss simply experience hormonal changes that trigger a shorter Anagen phase resulting in shorter, thinner hair. The Anagen stage will continue to shorten over time; this is why we lose our hair gradually and often over many years.
Proper nutrition is important in maintaining hair health but sometimes this won’t be enough. For this reason, hair restoration treatments are most effective when the follicles are in early stages of hair loss and alive.