You wash your hair and after that white froth covers your hands, you take a peek and find something else there. Black or blonde or brown strands of hair. A few of these strands are not bothering but when you find an alarming amount of hairs on your hand, the thought of balding starts to loom over your head. So how many hairs on the human head are there and how many can you afford to lose every day?
In a rough estimate, the average number of hairs in the human head is 100,000. Of course, these aren’t exact numbers but it is very close. That’s just on the head. There are around 25,000 body hair, 420 hair strands in the eyelashes, and 600 in the brows. These numbers come from Harvard’s Biobumbers department. All the relevant links will be provided below.
But there’s more. 100,000 hairs is the average number, but the number of hairs on the human head depends on the ethnicity of the human. Blondes have the most hair with an average of 150,000 strands of hair. Brown-hair people have around 110,000 hairs, black-haired people have 100,000, and red-haired people have the least amount of hair, averaging at 90,000.
This brings us to the next question; Why does ethnicity change the number of hairs? Also, why do blondes have so many hairs while red-haired people have the least? Let’s try and find the answer to these discrepancies.
Why Blondes have the most hair?
An average of 50,000 additional hair seems like an advantage, doesn’t it? The answer to this question lies in the function of hair. Why do we have hair and what’s the most important function of human hair on the head?
The hair on the head serves the purpose of protecting the head (scalp and brain) from the harsh sun rays (UV) and also serves as a shock-absorber, insulator, etc. The UV protection comes from the pigment melanin which also gives hair its dark color (same goes for the skin).
The percentage of eumelanin (that makes hair black) is the most in black hair. In brown hair, it is low, but not very low. In blonde hair, the eumelanin levels are very low. This translates to; Black hairs provide the best UV protection and blonde hairs provide very low protection and brown hairs sit in the middle.
From these observations, one can relate the number of hair and the protection they provide. Black works efficiently so 100,000 strands are fine. Brown is decent so 110,000 is enough. But blondes need more hair since the UV protection won’t be adequate with low eumelanin content. This is why they get 150,000 strands of hair.
What about redheads?
Redheads have the lowest number of hairs, around 90,000. And they also have the least amount of eumelanin in their skin and hair strands. This does not work very well with the observation that we established before. So what’s happening here?
Here’s the thing, the number of red-haired people in the world is very low, about 3-5% and they are mostly located in the northern region of our planet, mostly in a cold environment. These places receive a very low amount of sunlight. So having high pigmentations could work against these people (since sunlight is crucial for Vitamin D). This is the reason for the low melanin percentage.
But in areas with abundant exposure to sunlight such as tropical countries, redheads have the highest risk of sun damage and even skin cancer due to UV exposure. Blondes have a low content of melanin, but they still have 95% of eumelanin for protection against UV.
How much hair can you afford to lose every day?
On average, a normal human loses about 50-100 strands of hair every day. This is normal and often, people shampooing their hair find a frightening amount of hair strands in the drain. But that’s not the fallen strands of one day, but of many days. Even if someone loses 200-300 hair strands a day, it is normal. This is the average number during the telophase (shedding).
Hair falls and then new hair strands replace the empty space. The problem occurs when the rate of hair fall is not matched by hair growth. This is when balding occurs when the hair roots shrivel and no new hair strand can grow out. This is when you should seek medical attention and try and stop or even reverse it. This concludes the article.
Read more articles that might interest you:
- What is Hair Made of? And Which Part of it is Living?
- What are Fingernails made of and How is it Deeper than you Think…
- What is a Pinch Callus and Why do you get one?