Showing posts with label Hair Health. Show all posts
Showing posts with label Hair Health. Show all posts

Why do head hair grow more than other body hair

Hair on our scalp tend to grow much larger than other body hairs. Hairs on different parts of body have a certain fixed length and their length never exceed that limit. But do our head hair also have any such limit or they can grow infinitely. Even if they can reach a certain maximum limit, why do they grow comparatively longer than other body hair. We will try to find a satisfactory answer to these questions in this article.

Why do we have hair on our body ?  You may read this article before going further to increase your basic knowledge about your hair, not just hair on scalp. It tells about the basic necessity of hair. Same facts work for the scalp hair as well. Some factors made the head hair grow comparatively longer than other body hair. We will discuss those factors here.


Whatever we are now is due to adaptation. It is a biological process to make or modify our body according to need of our environment. In this process we loose some unnecessary features of our body and gain some new features to made our body adaptable to new environment. Hairs on our body also adapted to the changing environment. When our ancestors used to live in forests without much clothes to wear they had much more hairs on their body compared to today's human beings. Density and length of hairs on our body changed according to need and environment, but it took thousands of years for these changes to happen. Hair on head continued to grow longer than other parts of body for some reason.

Outer Appearance 

Outer appearance matters a lot in animal world. Mostly males of different species have longer head hair and beard to give them more masculine look and attract females to continue their genes. Man is also a social animal and adapted in the same way as other animals. In the modern world hair on our scalp are more an ornament for both ladies and gents. They can change you whole appearance and creates a social image of yours. However humans have evolved a lot but still we need these head hair to give us a proper look.


It protects our scalp from any external injury like cuts and scratches. Head is one of the most important organs as it contains the brain. Most of the time of the day we don't cover it and thus need more hair to give it proper protection.

  • Hairs acts as cushion and can decrease the impact of a collision on head and thus saves the brain. 
  • Hairs can also also protect us from ultraviolet (UV) radiation. Saving our brain from radiations might be a reason behind more dense and lengthy hair on head.
  • Hairs on head help in maintaining the temperature of our scalp. Now human beings have more hairs only on that part of body which are heat release zones, such as armpits and groin. More hairs means more tendency to produce sweat and control the temperature.

Science behind longer head hair strand

Our hair have three stages of growth: Anagen, Catagen and Telogen. Anagen phase is the real growth period of a hair strand. Telogen phase is the resting and shredding phase of hair. Between these two phases comes the catagen phase which is an intermediate stage. The duration of Anagen phase decides the length of hair.  Anagen phase duration varies from few weeks to years. Most of the body hair have anagen phase of only few weeks and thus remain shorter in length. But the head hair have anagen phase of years. It makes the head hair continue to grow for years and thus making them reach the length in feets. Anagen phase of our hair depends on our genes and thus some people are more hairy than others.

If you have got some additional information about longer head hair then you may provide your insight in the comments section.

Why do we have hair on our body ?

Modern human beings take body hair as something unclean and leave no chance to remove them from your body except head and eyes. The more modern you are, the lesser amount of body hair you will keep. But why do we hair on our body. This question must have come to your mind while getting a haircut. While i tried to find an answer to this question i noticed that all mammals have certain amount of body hairs. The amount of hair depends on their species and the climate of their habitat. But we the humans have different amount of body hairs even at the same geographic location. The amount of body hair depends on our genes but the real question is that why do we have them. What purpose of nature do they solve in our body? We have got nothing without any reason. Every organ has a specific purpose and their must be a reason behind hairs too. You will find an answer to this question in this article.

Hair on different parts of body solve different purpose. However some purpose are common but still their function varies according to their location on body.


  • Protection from cuts and scratches: Hair protects us from cuts and scratches. The more body hair you have got, the lesser you are prone to cuts and scratches. It makes us understand the high amount of hairs on scalp.
  • Protection from Malaria: It might sound funny but it is true. Body hair not just protect from malaria but any mosquito born disease. Hair on our arms and legs signals the presence on mosquito on skin even before it bites and our body reacts to not let the bite happen. Therefore kids are more prone to malaria than adults as they have less or negligible body hair.
  • Dirt Catcher: Hair in our nostril traps the dirt and thus filters the air we breathe. Wetness in nose helps the hairs in solving this purpose. Eyelashes also solves the same purpose and saves our eyes from foreign material.
  • Goosebumps protects you: However this feature is not as useful in humans as in animals like porcupines or other animals with more fur. Goosebumps is a feature that makes you look large when you are in fear. Goosebumps occur due to some other reasons as well but it happens at the time of fear also. An illusion of looking large can sometimes protect you from other animals.

As a Sensory organ

  • We hear through tiny hair follicles in our ear. These hair follicles feels the sound vibration and send signals to brain which translates it and understands the surrounding noise.
  • Hairs acts as an extension of our touching sense. We can feel a touch on our hairs because even a slight movement of body hair makes movement of the root skin which sends signals to brain. This feature saves us from mosquito bites as we feel the presence of mosquito just as it sits on our body.
There are some other interesting and least understood reasons for the presence of body hairs.
  • Temperature regulation: When we feel sudden coldness in environment, hairs on arms and legs get stand straight (goosebumps) to trap more heat near the body.
  • Hairs Facilitate sweating: sweating is also a mechanism to regulate body temperature and hair strands play an important role in this process.
  • Camouflage: Hairs act as camouflage for our reproductive organs. However it was necessary during during the evolution of humans, when our ancestors didn't have clothes to wear. 
  • Cushion: Hair in the armpits provides a cushion against friction of arms. Similarly pubic hair also saves our sensitive skin from skin friction.
  • Protection from pathogens: Usually we think that pubic hair is for no purpose but the biggest purpose of these hairs is protection of our reproductive system from pathogens, thus protecting them from any bacterial or fungal infection.

Interesting Facts about Hairs

  • Humans have nearly 5 million hair follicles on the body.
  • Head have the highest concentration of hair.
  • Nostril rank on second number in concentration of hair.
  • Hair grow on almost every part of our body except palm of hands, sole of feet and lips.
Our body actually need hairs but we keep removing them in order to look good. Trimming them is OK but removing them completely increases some risk factors. If there was no need of hair then we must have lost them in the process of evolution. But we do have them for some reason.