After washing your hair, is it better to let it air dry or blow dry? Most people do it wrong

After washing our hair, we often face a very difficult choice - should we let our hair dry naturally or use a hair dryer to dry it quickly?

How do you usually do it?

This is not a simple multiple-choice question, it also involves the health of the hair .

Dry with a hair dryer

Easy to style, but can damage hair quality and affect scalp health

1

Damaged hair

It is true that hair dryers can damage hair. The hot air from a hair dryer can make hair dry, brittle, split, and break easily.

To understand why, we need to first understand the microscopic structure of hair.

A hair strand looks like a strand to the naked eye, but if you look at it under a microscope, you will find that its internal structure is a bit complicated. From the center to the periphery, it consists of the medulla, cortex, and scales. The scales are actually a layer of epidermal cells that cover the surface of the hair like small armors, forming a protective barrier.

The hair scales on the hair under an electron microscope. Image source: Wikipedia

Hair scales play a big role. They can prevent the loss of protein and moisture inside the hair, maintain the health and strength of the hair; they can also reduce the friction between the hair and the external environment, reduce hair damage, breakage and split ends; the coverage of hair scales also prevents external dust and chemicals from entering the hair, effectively avoiding the damage to the hair caused by these bad things.

If you want your hair to look good, you must first protect the outermost layer of hair scales, which is equivalent to the face of your hair. If the hair scales are intact and tightly closed, your hair will look healthy and shiny; if the hair scales are damaged or not tightly closed, your hair will look dry and frizzy.

This layer of hair scales has a characteristic that it is in a closed state when dry, tightly attached and connected to each other, but when it encounters water, the hair scales are in an open state, like small mouths opening towards the sky.

After we wash our hair, when it is still wet, we use a hair dryer. When the hot air blows through the surface of the hair scales, the angle of the opening of the hair scales will be blown larger. At this time, the moisture inside the hair will be taken away by the hot air faster, causing the hair to lose water and become dry over time.

The high temperature and strong wind generated by the hair dryer can also cause damage to the hair scales . Once the hair scales are damaged, not only can they not effectively protect the hair, but as more damaged hair scales appear, the hair surface will become rough, leading to increased friction between the hair and further damage to the hair.

At the same time, high temperature will also destroy the disulfide bonds in the hair keratin, causing the keratin to denature . This is also the main reason why hair becomes brittle and easy to break after frequent use of a hair dryer.

At the same time, the pigment in the hair will also be destroyed under high temperature. Most of us yellow people have black hair. After the melanin in the hair is destroyed, the hair tends to turn yellow. This is why we see people who often use hair dryers have some yellow hair.

In contrast, the benefits of letting your hair air dry naturally after washing are obvious. Natural air drying can avoid a series of damages to the hair caused by high temperature and strong wind, help maintain the hair quality, and give the hair a natural luster and healthy beauty.

2

Affects scalp health

In addition to damaging the hair quality, using a hair dryer may also have a negative impact on the health of the scalp. We also need to understand the reasons behind this from the microscopic structure of the scalp.

The surface of our scalp is covered with a thin layer of stratum corneum, under which are abundant capillaries and nerve endings. The stratum corneum is a protective barrier that can maintain the moisture balance of the scalp, block the entry of harmful substances such as dust and bacteria from the outside, reduce scalp infection and inflammation, and also reduce the damage of ultraviolet rays, chemicals and other irritants to the hair follicles growing inside the scalp, thus maintaining the growth and health of hair.

However, when the hot air from the hair dryer blows onto the scalp, the high temperature will accelerate the evaporation of moisture on the surface of the scalp, causing the stratum corneum to become dry. This dry state may cause itching, dandruff and other phenomena on the scalp.

At the same time, prolonged or excessive use of a hair dryer may damage the stratum corneum of the scalp and impair the barrier function of the scalp.

Long-term high temperature stimulation will also affect the capillaries under the scalp, causing capillary dilation, making the scalp red and congested. In severe cases, it may cause scalp inflammation, pain, and burning sensation.

In contrast, if you choose to let your hair dry naturally after washing it, you can avoid the damage to your scalp caused by the high temperature hot air from the hair dryer.

3

Easy to style

The hot air generated by the hair dryer can change the shape of the hair. When the hot air blows towards the hair, the moisture in the hair will be heated and evaporated, causing the hair scales to open, making the hair soft and increasing its plasticity.

At the same time, when the hair is in a soft state after being heated by hot air, turning on the cold air mode of the hair dryer can quickly cool the hair and shape it, making the special style more lasting.

Air dry

Avoid hair damage caused by high temperature of hair dryer

But cold weather may irritate the scalp

So, does it mean that using a hair dryer to dry your hair is useless, and choosing to air dry your hair is beneficial without any harm? That's not the case.

Waiting for hair to dry naturally usually takes a long time, especially for girls with long hair. It takes too long to wait for long hair to dry naturally. If you rush to do other things at this time, it will bring inconvenience.

Moreover, many people like to take a shower before going to bed at night. Sleeping with wet hair is not good for health. Not only is it easy to catch a cold, but the hair scales of wet hair are open. As the head moves during sleep, the hair scales will be damaged due to friction, which is even worse for the hair quality .

When washing our hair in winter, if our hair is not dry yet, we rush to go out and walk into the cold and windy outdoors with wet hair. The sudden drop in outdoor temperature will cause the temperature of the hair and scalp to drop sharply, causing the scalp to be stimulated by the cold, leading to problems such as cold or migraine; it will also cause the hair scales on the surface of the hair to close too quickly, making the hair fragile and easy to break; the cold wind will blow away the moisture in the hair, making the hair even drier.

Which method should I choose to dry my hair?

In fact, it mainly depends on your personal needs.

If you have plenty of time, don't need to style your hair, and want to protect the health of your hair and scalp as much as possible, then air drying is definitely a better choice for you.

But if you are short on time and need to dry your hair quickly or style your hair, then a hair dryer is undoubtedly your good helper. Using a hair dryer once in a while will not cause too much damage to your hair and scalp. What we need to avoid is long-term and frequent use of a hair dryer.

Copyright images in the gallery. Reprinting and using them may lead to copyright disputes.

If you really need to use a hair dryer, the recommended method is:

First, use a towel to gently absorb the excess water on your hair. Be careful not to rub it vigorously. When your hair is half dry, use a hair dryer to complete the final blow-drying or styling.

Or you can use a hair dryer for a while, then stop using the hair dryer when your hair still feels a little damp, and then let your hair dry naturally.

In addition, there are 2 points to note:

1

Use cool wind mode and minimum wind speed as much as possible

Try to avoid always using the hot air setting and high wind speed of the hair dryer to dry your hair. Please try to use the cool air setting and low wind speed, maintain an appropriate distance, follow the principle of "the wind should not burn the skin", and avoid blowing the air to the same part of the hair and scalp for a long time.

2

Blow dry the roots first, then the ends

Many people like to blow dry the wet ends of their hair first. Of course, this can prevent the water from the ends of the hair from dripping onto clothes and the floor, but in fact, the water at the roots of the hair will still drip down along the hair strands, and in the end, the ends of the hair will have to be blown dry again, causing secondary damage to the ends of the hair. We recommend blowing dry the roots of the hair first, dry the scalp at the same time, and then blow dry the ends of the hair.

In general, whether it is air drying or using a hair dryer, each has its own advantages and disadvantages. The key is to choose the most suitable method according to your own situation and needs. While protecting your hair quality, you can also take into account the convenience and comfort of life. I hope this article can help you make a better choice and keep your hair healthy and beautiful.

Planning and production

Author: Zeng Xinyue, popular science creator

Reviewer: Tang Qin, Director and Researcher of the Medical Science Department of the Chinese Medical Association

Planning｜Yang Yaping

Editor: Yinuo

Proofread by Xu Lailinlin