You may have heard that a dry scalp is bad, but a former hairdresser and doctor will explain how a dry scalp can actually have a negative effect on your hair.

Effects of dryness on the scalp

Human skin, including the scalp, has a barrier function.
The skin is made up of the epidermis, dermis, and subcutaneous tissue, but when the scalp becomes dry, the keratin in the epidermis cracks, which causes UV damage and bacterial invasion.
Dryness can be said to be the cause of ``a loss of the skin's barrier function, which can cause various problems.''

Symptoms of dry scalp

Dandruff and itchiness are symptoms that are easy to notice when your scalp is dry. The keratinocytes that cause dandruff are normally so small that they cannot be seen by the human eye, but when dryness disrupts the turnover cycle of keratinocytes, dandruff becomes large enough to be seen.

Itching can be divided into congenital and acquired.
There are people who are born with a skin with low moisture and sebum, and there are people whose skin has low moisture and sebum due to lifestyle habits.

Additionally, the scalp has twice as many sweat glands and sebaceous glands as the facial skin, meaning that it secretes more sweat and sebum than the facial skin.
On the other hand, it has a low ability to retain moisture and is prone to drying out.
In such an environment, the scalp is a delicate part that is prone to problems.
As a doctor, I believe it is necessary to provide proper care.
I couldn't find any research papers that show that dry scalp causes gray hair or hair loss.

Does dry scalp cause gray hair or hair loss?

From a hairstylist's perspective, we will answer whether your scalp condition is causing gray hair or hair loss.
First of all, people who have severe symptoms of atopic dermatitis or allergies have naturally low moisture and sebum in their skin, and in my experience, I have never seen anyone with such symptoms suffer from thinning hair.
If anything, gray hair, stiff hair, and curly hair are more common.
On the other hand, people with oily scalps are less likely to suffer from gray hair or stiff hair, and more likely to have thinning hair.

I believe that the type of skin you have has an impact on what things grow.
By looking at my scalp, I can now roughly understand what kind of hair grows.

Scalp care you can start today

Dryness can lead to dandruff and itching, as well as deterioration of hair quality and gray hair, so we will explain how to care for your scalp starting today.
First of all, we recommend shampooing your hair every other day, which most people do every day.
Rinsing thoroughly will remove some of the dirt, so use only hot water on one day and shampoo on the other day.
Furthermore, avoid using shampoos that contain ``sodium lauryl sulfate'' or ``sodium laureth sulfate.''
Both are ingredients with high cleaning power, similar to those used in dish detergents.
Surfactants that have a strong ability to break down water and oil cause scalp dryness.

Summary

① Dry scalp causes dandruff and itching.
② Shampooing too much can cause dry scalp.