Ever since the dawn of time, humans treat their hair less than an ornament. It makes the face complete – it is like the cherry on the top – it is versatile and is great in general. But our precious hair is not immortal and is very susceptible to fall out. Regardless of the age, sex or lifestyle, HAIR FALL is a completely common, normal and healthy process. It is common to lose hair strands in the range of 50 to 100 per day. Although this number seems to be big, the rate of regeneration of hair evens the loss out.
A clear indication of ageing is seen in men and women, especially by looking at their hair. As the age progresses, the hair tends to lose its pigmentation and GREYING of the hair is noticed. While women experience greying coupled with thinning of hair on the scalp, men witness a drastic decrease in hair and show signs of BALDNESS. How hair starts to fall out in men is generally called PATTERN BALDING. Pattern baldness is observed mostly in men – why not in women?
Are male and female hair different?
This discussion excludes hair on different parts of the body and only focused on the head. Human males are generally observed to have short hair, while females are seen to have long hair. In reality, this difference in the hairstyle is a societal norm instead of a biological one. Men can grow out their hair to be as long as the females’ and women can crop their hair like that of males.
Women’s choice to don longer hair is due to the perception of fertility. We are evolutionarily wired to conform to the stereotypical appearance of a woman and deem her fertile. As for males, their hair length is considered irrelevant to their fertility. Thus, the male and female hair is the same and it depends on the individual to keep it as they wish.
Since it has been established that the hair of men and women is identical, it is logical to wonder why baldness only affects men. The length of the hair is irrelevant in the case of hair loss, thereby understanding that shorter hair does not correspond to hair loss. Since hair grows from the hair follicles present under the skin of the scalp and not from the lower tip of the hair, one cannot judge the rate of growth of the hair. However, hair loss and growth is unique to a person and has little to do with their sex.
So, why don’t women experience balding?
Surprisingly, the reason for male pattern balding goes to the level of GENETICS. The most common reason for balding in men is HEREDITY. Some researchers consider balding as a GENETIC DISORDER – one which can only affect men. One of the most popular instances of male pattern baldness is a genetic disorder is seen in the Royal Family of the UK. Prince William had started showing signs of baldness around the age of 35 since it was passed on to him from his father, Prince Charles – and Prince Harry will soon follow the same path.
To understand hereditary baldness, one must understand the genetics of sex. Humans have 23 pairs of chromosomes – the last pair of which are called SEX CHROMOSOMES. The genes contained in the 23rd pair of chromosomes are the ones which determine the sex of an embryo in the womb. The female gamete or OVUM contains the sex chromosome X, while the male gamete or SPERM carried either the X or Y chromosome. If the ovum is FERTILISED by the sperm carrying the X chromosome, the resultant zygote will be a female with the sex chromosome pair XX. If the sperm carrying the Y chromosome fertilises the ovum, the zygote will develop into a male with the sex chromosomes XY.
GENETIC DISORDERS are passed on through the chromosomes. Any deviation from the normal leads to a genetic disorder in the resultant zygote and will manifest in the person throughout their life. As of now, most genetic disorders are UNCURABLE. Pattern baldness observed in men is a consequence of a SEX-LINKED genetic disorder.
The genes which cause male pattern baldness are located on the Y chromosome, giving it the term of being a Y-LINKED genetic disorder. When an ovum is fertilised with the sperm carrying a Y chromosome with the genes causing baldness, the progeny will experience baldness in his life. Since the Y chromosome is not found in females, women do not suffer from pattern baldness.
That being said, this is not the only reason for baldness. While it is considered the biggest reason for male pattern baldness, there are other reasons which can contribute to the thinning of hair. Genetics in general (from the mother and father) also determine the appearance of the hair – from the colour to the loss of hair strands.
Balding also occurs as a result of environmental factors, stress and the overall health of an individual. However, these causes are not selective towards gender and occur in both genders equally. Other than an autoimmune disease called ALOPECIA, where the immune cells of the body recognise the hair follicles as foreign and sought to kill them, none of the other factors causes a permanent hair loss in men and females. The distinguishing feature of hereditary male pattern baldness is that the strands of hair loss in a portion of the scalp never regrow.