Why does straight hair change into curly hair?

"When I was a child, I had straight, silky hair, but as I got older, it became curly."
"I want my hair to go back to being straight like it used to be."
"I wonder why my hair texture has changed..."

When people think of curly hair, they often picture "naturally permed" hair that they were born with.
However, the swells gradually intensify after puberty and into adulthood.There are many people who say, "My hair used to be straight, but now I'm troubled by curly hair."

In fact, recently at Dr. TOUHI CLINIC, we've received a series of consultations from patients who are suffering from hair frizz, all following a very similar course of events, due to a certain common factor.
Furthermore, by chance, we discovered that several children of our hospital staff were experiencing the same problems at the same time.

I will discuss in detail the "common background," the surprising causes of hair quality changes revealed by this intriguing fact, and the correct solutions for restoring healthy hair.

Changes in hair texture that appear after puberty

I've been receiving a series of consultations from boys who, after dedicating themselves wholeheartedly to baseball in their middle and high school clubs, started growing their hair out to enjoy fashion after graduating from high school. They've noticed that their hair texture has changed and it's become much more curly, and they're deeply troubled by this.
Even if you are still young, in your late teens or early twenties, if your hair is becoming increasingly curly, it is highly likely that the "aging of the scalp" has already begun.

Those who play sports outdoors every day without a roof, especially baseball players, are inevitably exposed to large amounts of ultraviolet radiation on a daily basis.
Most people are concerned about sunburn on their face, but probably don't think about protecting their scalp from UV rays.
UV damage accumulated over many years will definitely worsen the condition of your scalp.
When examining the scalps of people with these kinds of problems using a microscope, we very often find that they have numerous spots and moles on their scalps.
All of this is due to the accumulation of ultraviolet radiation exposure from the past.

Don't underestimate the impact on your scalp just because you're young; if you're actively involved in outdoor activities, it's important to be aware of the effects from an early age.

The harmful effects of ultraviolet rays

So why does exposure to ultraviolet rays lead to "curly hair"?
The mechanism is exactly the same as that of aging skin on the face.
If the scalp is continuously exposed to strong ultraviolet rays, it can cause dryness and inflammation of the skin, accelerating skin aging.

As a result,Invisible wrinkles and sagging may begin to appear on the scalp.
When the scalp sags, the shape of the pores and hair follicles inside the skin becomes distorted and deformed.

When my hair was naturally straight, the hair follicles also maintained a beautiful circular shape.
However, when the scalp ages due to UV damage and the hair follicles become distorted, the hair that grows from them will also be pushed out in a bumpy, wavy state.
This is the true reason why hair that was straight gradually becomes curly.

When straight hair starts to develop these bumpy, wavy strands, it's an important sign of aging from the scalp.
Leaving this condition untreated can lead to an increase in gray hair and further hair problems, so early care is important.

Harm caused by incorrect measures

When hair becomes more curly or frizzy during your teens or twenties, it tends to become unruly and difficult to manage, which can be a source of significant frustration.
Driven by a desperate desire to straighten their hair, many people resort to "hair straightening treatments" or try to force it straight with a hair iron every day.

However, these measures can actually be counterproductive, so as a specialist, I cannot recommend them.
When you get a hair straightening treatment, your hair temporarily becomes straight, shiny, and looks neat and manageable.
However, repeatedly doing this not only severely damages the hair itself, but also inflicts significant damage on the scalp due to the chemicals and heat.
As a result, it can further accelerate scalp aging, leading to a vicious cycle that actually worsens frizzy hair.
If you're looking for a fundamental solution, it's important to minimize chemical straightening and excessive use of hair irons, and instead choose options that are kind to your scalp.

▼Things you should see before getting a hair straightening treatment: fundamental solutions for curly hair
 

Hair care and styling you can incorporate into your daily routine

During periods when frizz and volume are a concern, instead of trying to force your hair straight, it's more effective to first try hairstyles and styling techniques that make the most of your natural curls.
People with curly hair have a characteristic that makes it difficult to achieve shine due to the structure of their hair.
Therefore, I recommend using hair oil.

Using oil while blow-drying helps to control frizz and keep hair neatly styled, while also providing much-needed shine.
Alongside these daily styling techniques, the most important things are "protecting your scalp from UV rays" and "moisturizing care."
If you haven't done any scalp care before, simply applying a scalp serum to your scalp after shampooing every day to properly moisturize it can improve your scalp environment and lead to faster positive changes in the quality of new hair growth.
The younger you are, the more smoothly you can expect to see results when you start the care.

▼This article provides a detailed explanation of the relationship between the scalp and UV rays, as well as UV protection measures.
 
Furthermore, Dr. TOUHI CLINIC also offers hair quality improvement treatments using injections that directly target the scalp.

▼Case studies of improving curly hair
 

By consistently combining these regular professional treatments with home care, it is entirely possible to repair the damaged foundation and restore your hair to its original smooth and silky texture.

Summary

This article explained the reasons why hair texture changes from straight to curly, and how to address this issue.
You might be surprised to hear that the reason your hair texture has changed is due to "scalp aging caused by past UV exposure," but just like with facial skincare, if you start taking the right measures now, you can guide your scalp back to a healthy state.
If you're struggling with suddenly developing curly hair and don't know what to do, or if you don't want to keep getting chemical straightening treatments, instead of just trying to fix the surface of your hair, please take a look at your scalp for a change.
At our clinic, we offer personalized care and treatment tailored to each individual's scalp condition.
If you have any concerns, please feel free to come and talk to us.