The problem of hair loss
The life cycle of hair
To understand the causes of hair loss, we have to know the stages of the life cycle of the hair. Hair is constantly renewed. The life cycle of hair has three stages that continue to follow each other under normal conditions:
- The anagen phase (3 to 5 years) – the growth phase
- The catagen phase (3 weeks) – the transition phase
- The telogen phase (3 to 4 months) - the shedding phase.
Each hair is at some stage of development. When the cycle is completed, new hair starts to form. The speed of hair growth is cca. 1.25 cm per month, the average lifespan of each hair is 2 to 7 years. A normal, healthy head of hair has approximately 100,000 hairs growing.
The longer the hair stays in the anagen phase, the longer it will grow. Cca. 85 % of the hairs are in the anagen phase. 10 to 15 % of the hairs are in the other two phases.
The problem of excessive hair loss appears when a majority of hairs mature early and simultaneously pass into the third phase. Each new anagen phase is shorter and the new hairs are ever shorter and thinner.
Loss of hair is a normal occurrence. Normally 60-80 individual hairs fall out each day. However, when 100 or more hairs fall out on a daily basis, we are talking about increased hair loss. When this occurs, the number of hairs in the anagen phase (the active growth phase) reduces while the number of hairs in the telogen phase (the shedding phase) increases.
Hair loss can be caused by a variety of conditions, including: family history (heredity), hormonal changes, medical treatments, medications, stress…
The most common type of baldness is androgenetic alopecia or so-called male pattern baldness. It usually occurs gradually and in predictable patterns — a receding hairline and bald spots in men and thinning hair that begins in the centre of the scalp in women.
Hereditary baldness in men appears after the age of 20 and worsens over time. It affects over 50 percent of men over the age of 50. Hereditary baldness is rarer in women and mostly appears in the menopause.