non-scalp hair follicles per square inch

It’s often said that we have appx 1,000 hair follicles per inch on our scalp. I’m wondering if there are any stats. on follicles-per-inch on other parts of the body, including armpits, lower legs, and bikini area.

Also, of the total follicles per inch, do we know what percent are actively-growing terminal hairs vs. vellus hair and follicles which are inactive but able to produce hair with the right hormonal stimulus?

Thanks much–an hour of browser searching has brought little in the way of factual information.

According to my data:

area …follicles per square Cm

Upper lip … 500
Chin … 500
Pubic … 70
Underarm … 65
Arm … 80
Thighs, legs … 60

Hello, what about other areas such as chest and back?

More studies are needed on hair growth. Charts like this only serve as a guideline. There are variables involved and no two people are alike.

Growth Table About Hair Cycle And Phase
Duration At Different Anatomic Body Sites

Body Site % Anagen (growing)Hairs % Telogen (resting) Hairs Duration of Anagen Duration of Telogen Density per sq.cm Depth of Follicle
Scalp 85% 15% 2-6 years 3-4 months 350/sq.cm 5-7mm
Beard 70% 30% 1 year 10 weeks 500/sq.cm 2-4mm
Upper Lip 65% 35% 16 weeks 6 weeks 500/sq.cm 1-2.5mm
Armpit 30% 70% 4 months 3 months 65/sq.cm 4-5mm
Chest/Back 30% 70% 3 months 70/sq.cm 2-5mm
Breasts 30% 70% 4 months 70/sq.cm 2-4mm
Arms 20% 80% 13 weeks 5 months 80/sq.cm 2-4mm
Legs 20% 80% 16 weeks 6 months 60/sq.cm 2-4.5mm
Pubic Area 30% 70% Months 3 months 70/sq.cm 4-5mm
Eyebrows 10% 90% 4-8 wks 3 months 2-2.5mm
Male Cheeks 50-70% 30-50% 880/sq.cm 2-4mm

There is a name I recall from years ago…Szabo and body hair count…so I looked for it. Early on, I’d read that Szabo (in the 1950s) had determined there were about 2 million hair follicles on a body, and that half were on the head! Since then, I’ve read that we may have as many as 5 million hair follicles on our body…but cannot find WHERE I read that!

Preparing to download ... This article has some names you will recognize…Montagna and Ferriman

Here’s an abstract of “The Regional Anatomy of the Human Integument with Special Reference to the Distribution of Hair Follicles, Sweat Glands and Melanocytes” http://rstb.royalsocietypublishing.org/content/252/779/447 that I would love to read the full article…

Hair Follicle Size and Distribution: http://www.nature.com/jid/journal/v122/n1/full/5602116a.html#bib15

2 to 5 million hairs? wow…but I think about 1.5 million went on a permanent vacation from my head and migrated elsewhere lol.

If you need the information as an academic issue… OK but otherwise
SO WHAT!!! You mention forearms, All hair growth is caused by male hormone (even on women). If it is specifically on forearms and lower legs (the extremities) it most often is caused by polycystic ovaries. 20 -25% of all women have this problem at autopsy. It is very common but in different degrees. Many women ignore it because they think it is part of their genetics, however, when they want to have children it MIGHT BE A PROBLEM. They used to be married at 17-18 and had their kids before 25. Now they get married later and start to have kids at 25-30 and later. That is when it becomes a problem. Age has a lot to contend with here. As a woman matures her fertility tends to decline. If getting pregnant is a problem and she has too much hair…poly cystic ovaries is a strong possibility.
The number varies with genetics, idiosyncratics of individual patient, gender, and so many other conditions that doctors do not care. When you go to a doc he examines you and listens to your story, asks a few questions (maybe), may order some tests, and then prescribes something to make you feel better. That is his job. Many conditions have no cure. He will try to make you feel better but the time it takes to explain everything to you (if the patient can comprehend it all) takes too long.

Hair follicles. There’s a difference. Not all of your hair follicles will be growing a hair at any given time. That’s the great mystery - just how many are growing at any one time - or even this year?

Something I do tell clients: If a high percentage of all of our hair follicles were turned on, then we would all look like the two brothers who are known as the Wolf Boys. http://www.listentome.net/stuff97.php

You still have all those follicles on your head - they are just…on permanent vacation…

they’re lazy like me! LOL

I’ll dream for now of having a full head of hair and little to no hair on the torso/back. :slight_smile:

Have a good week everyone! :slight_smile: