Why isn’t my hair growing all at once or coming in evenly?

Last updated on September 21, 2020



I am a 13-year-old, and I have some different questions.

First, last week I was curious to see if I had armpit hair because I already have hair on the upper lip, and when I looked I saw very short whitish hairs forming. When will they grow out? I already have pubic hair that is longer, darker, and curlier than this hair and it has been bothering me why they aren’t growing at the same rate.

Also, why is my pubic hair growing so oddly? There is like twice as much on the right side as there is on the left, and it constantly bothers me.

Lastly, why does my pubic hair seem to be thinner at other times? Sometimes, I notice that it looks much fuller at some times, and at other times it looks thin.

I am in estimated somewhere in tanner stage 3.


People have two types of hair, vellus and terminal hair. You have terminal hair on the top of your head and as a child, you had vellus hair most everywhere else. About the only places you don’t have hair is on the soles of your feet and the palms of your hands.

Vellus hair is fine (small in diameter) and without pigment, so it is mostly clear. Because it is so fine, it breaks off easily and doesn’t tend to get very long. It is also very soft to the touch.

Terminal hair is thicker in diameter and pigmented. It will grow much longer than vellus hair.

What you have right now under your arm are vellus hairs. As these hairs change to terminal hairs, they will first grow long. It is hard to see the vellus hairs straight on. Eventually, they will take on pigment and get darker.

The hairs don’t develop all at the same time. Each hair follicle is on its own clock. The reason for this is that the follicles have to rest periodically. During that resting time, the hair breaks off. If the follicles all developed at once, then they would rest at the same time and you would be shedding like a dog or a cat. Instead, a follicle here and there rests for a period. You lose the hair but in the midst of all the other ones you don’t notice it.

But what that means is that initially, it takes a while for all the hair to come in since they start one at a time. Your body also spreads out development to not use up all your energy at once. Pubic hair develops before underarm hair.

Not everyone is perfectly symmetrical so I suspect that the once side is a bit behind the other side, but it will eventually catch up.

Your hair doesn’t change size, but it will lay differently depending on the amount of oils that accumulate on the hairs. Clean hair is fluffier and curls more. Oily hair is straight and lies flatter.