Anagen – the active growth period
Catagen – short recession period
Telogen – resting period.
Hair that reaches the end of its life is shed and healthy new hair grows in its place.
Within this growth cycle, daily loss of about 100 hairs is considered normal.
Causes of Hair Loss/Male Pattern Baldness
Male pattern baldness, also called androgenic alopecia, can be as a result of genetics or having a family history of baldness. Thinning hair can occur due to environmental factors, air pollution, stress, illness, overuse of chemicals on hair or medication.
Male Pattern Baldness
- Hormones – Testosterone, a male hormone (androgen), is converted to DHT (Dihydrotestosterone) -explicit result is hair loss.
The first signs of this genetic predisposition appear after puberty between 20 and 30 years. First, the hair pulls back along the end line, then the flow of history with ever thinning hair away at the crown. In some men, this can expand all over the head. However, many keep their hair at the temples and at the nape.
The interaction of different factors
In androgenetic alopecia accordingly three factors play an important role:
Age of person
If a person has a genetic predisposition to lose hair, this will generally result in slowing the regrowth of hair. In both women and men the production of endogenous growth factors such as IGF-1 (insulin-like growth factor), KGF (keratinocyte growth factor) and VEGF (vascular endothelial growth factor) decreases as they grow older and hair that has fallen out does not grow back due to lack of growth stimulation.
Hormones affect the length of the hair cycle and the division activity of the hair follicles.
As early as 20 years of age, the production of growth hormone HGH (human growth hormone) decreases. Every ten years this reduces further by 14% and this affects hair regrowth.
The enzyme 5-alpha-reductase
The male sex hormone testosterone is converted by the enzyme 5-alpha-reductase into dihydrotestosterone (DHT). DHT damages and weakens the hair roots. The enzyme 5-alpha-reductase exists in two types:
- as 5-alpha-reductase I (5aR1) in the front part of the scalp
- as 5-alpha-reductase II (5AR2) in the entire scalp
In people with an inherited hypersensitivity to DHT, the phase of hair growth (anagen) is shortened and results in a decrease in the length of hair. A bald man does not fewer hair follicles as a man with full hair growth, but because of the shortened growth phase the hair is barely visible. The scalp at the back and in the neck area is less sensitive to DHT generally.
Hair loss due to unbalanced and inadequate nutrition
Iron, zinc, sulfur and the vitamin B group care for healthy hair.