Moisturizing is the second and very critical step of basic skin care. The water content of the stratum corneum of the skin is generally between 20% and 30%. When the water content is below 10%, the normal metabolism of the stratum corneum cannot be carried out, and the function is affected. The skin will become rough and taut like dry land, with dry flaking and dehydrated fine lines, or even chapped, easily causing skin problems. If the skin is well moisturized, the stratum corneum cells absorb water, the skin will become soft and smooth, look transparent and textured, and other whitening and anti-aging skin care products are more easily absorbed. Moisturizing is the easiest and fastest way to see results in all skin care, and the method is simple: the right skin care philosophy plus the right moisturizer. 1.Why does the skin become dry? The stratum corneum of normal skin can form a complete “membrane” to prevent water loss and protect the internal structure from damage, which is called the “barrier function” in medical science. In dry skin, the barrier function is compromised and the “protective film” is no longer intact. As a result, the skin loses water, electrolytes and other substances through the epidermis, which makes the skin even drier and creates a vicious cycle; at the same time, external harmful or irritating substances can easily invade, leading to skin allergies or infections. There are many reasons that cause the barrier function to break down and make the skin dry. (1) Many people are born with dry skin, which is related to heredity and can be improved by later care. (2) Incorrect lifestyle habits are common causes of dry skin, such as frequent hot baths with too high a temperature, including showers, using strong cleansing and oil control acne products, bathing with alkaline soaps, etc. This tends to destroy the normal lipids on the skin surface and aggravate dry skin. (3) Environmental factors, such as cold, dry, frequent use of air conditioning, windy weather, etc., can aggravate dry skin. Using a humidifier indoors can relieve the discomfort caused by dryness, and can also help the skin to retrieve the lost moisture, which is a good choice in the winter in the north. (4) Patients suffering from some diseases, such as hypothyroidism and uremia, are prone to dry skin; taking some special medications, such as taking lithium preparations or retinoids, can lead to dry skin. (5) Excessive mental stress will affect the skin’s self-repair and aggravate the dryness of the skin. (6) Age factor can not be ignored, after the skin aging, the repair speed is slow, at the same time, due to the reduction of the synthesis of natural moisturizing factors, the skin’s water retention capacity decreases, so it is more likely to dry. 2.How to choose the right moisturizer for you? A good moisturizer is a must-have for every beauty-loving girl. It can provide you with long-lasting protection and feel at ease and comfortable even in a dry environment. There are many different types of moisturizers on the market today, and regardless of the changes in appearance and fragrance, the main active ingredients in moisturizing skin care products are divided into three types: encapsulants, moisture absorbers and emollients. The different moisturizers are different ratios of these three types of substances. (1) sealing agents are generally oils and fats that can form a film on the skin surface to prevent evaporation of water from the skin surface, such as petroleum jelly, mineral oil, paraffin, sharkene, vegetable oil, animal oil (such as lanolin), silicone, etc. Silicone resin is a new type of encapsulant, which is characterized by non-comedogenic, hypoallergenic, and non-strong odor, and is often found in “oil-free formula” moisturizers sold in the market. (2) Moisture absorbers are substances that can absorb moisture. Commonly used are: glycerin, propylene glycol, urea, sorbitol, honey, pyrrolidone alkene carboxylic acid (PCA) and so on. They are not selective in absorbing moisture, and can absorb moisture from the environment when the humidity is high, or from the skin if the environment is particularly dry, which can dry out the skin if used alone. So using glycerin alone is not a good moisturizing method, it must be used together with encapsulants to provide effective moisturizing effect. (3) Emollients are compounds that include a large group of compounds ranging from esters to long-chain alcohols. The long-chain alcohols fill in the cracks between dry skin keratinocytes when applied, making the skin soft and smooth. Commonly used ones include:cetyl stearate, C12-15 alkyl benzoinate, castor oil, simmondsia oil, isopropyl palmitate, dioctyl maleate, etc. The way to judge a good or bad moisturizer is very simple. You just have to try this product on your face or body and the way your skin feels is the best answer. A good moisturizer will provide a long-lasting moisturizing sensation and leave the skin moist, smooth and supple after use. It is important that the texture of the moisturizer is fresh, absorbs well into the skin and is not greasy and oily at all, which is good for oily skin. It is also very practical for those who need to wear makeup, you can use foundation and sunscreen directly on top without worrying about “mud”. No one moisturizer is perfect, and there are different formulations to meet different needs. As long as you choose carefully, there is always one for you. 3, moisturizing spray can not moisturize? It is your use of the wrong way many professional women will find that the office open enough air conditioning is the culprit of dry skin injury. The air conditioner takes away the cold or sweltering heat, but also takes away the moisture in the room. With very low humidity, the skin is like a humidifier that is left on for a long time, losing a lot of moisture without realizing it. That’s why spray lotions and spa waters are so popular. The advantage of spray lotion is that it does not ruin your makeup and provides a cool, moist feeling, and can be used even on makeup-wearing skin. However, many people find that the long-term use of sprays does not improve the phenomenon of dry and fragile skin, and seems to aggravate. This is because when sprayed with mineral water in dry air, the water evaporates particularly quickly and the moisture on the surface and inside the skin is “grabbed” by the dry air, causing the skin to become even drier. If you read the instructions carefully, you can find that most mineral water sprays are not primarily moisturizing, but rather anti-allergic, soothing effects. So you want to use the spray to save the “thirsty” skin is not the right choice, want to quench the thirst of the skin in the dry room, you must use the spray at the same time use moisturizer for the skin to lock moisture, in order to bring lasting moisturizing effect for the skin. 4, does oily skin need to use skin care products? Many people with oily skin are deeply troubled by oiliness and always want to get rid of the oil on their face. You will wash your face several times a day with cleanser, use oil control shrinkage water, oil control mask, but rarely use moisturizer. This is a very wrong approach, oily skin also needs moisturizing. First of all, it is important to understand the concept that oil control and hydration are not contradictory in any way. Oil is mainly secreted by the sebaceous glands, while water is an important part of the protective barrier function in the skin’s stratum corneum. People with oily skin often have problems with over-cleaning because they produce a lot of oil. In addition, oil-control cosmetics have the effect of drying out the skin to a greater or lesser extent. If the skin is acne-prone, coupled with the irritation of acne medication, the skin will often be in a state of oil and dehydration, manifested as oily T-zone and flaky cheeks. The skin will become sensitive in this dehydrated state for a long time, and the cosmetics used in the past will feel irritating, and if acne grows, many drugs will not be tolerated, and it will not only be a matter of aesthetics at that time. If you have oily skin, it is recommended that you wash your face in a gentle way and do not use too much scrubbing and alkaline cleansing milk and soap to avoid damaging the skin’s barrier. In addition, choose a moisturizer with a refreshing texture and insist on using it, especially for those who are using medication for acne treatment and need to protect the skin barrier function to increase the tolerance and efficacy of the medication. Tips: The skin is located in the outermost layer of the human body, from the outside to the inside is the epidermis, dermis and subcutaneous tissue. The skin is the natural barrier between the body and the external environment, and it is vital to maintain the relative stability of the body’s internal environment in the changing external environment. Without the skin, people cannot survive. Without a complete and healthy skin to maintain the relative stability of the internal environment of the organism in the external environment, the skin is vital. Without skin, people cannot survive. Without a complete and healthy skin, the quality of life will also be greatly reduced. The epidermis is located in the outermost layer of the skin and is divided from outside to inside into the stratum corneum, the stratum granulosum, the stratum spinosum and the stratum basale, which is constantly growing new cells. There are no blood vessels in the epidermis, but it is the fastest growing, renewing once every 1.5 to 2 months. The stratum corneum is crossed and overlapped by one or twenty layers of dead cells. If you don’t take a bath for a long time, you can rub out mud (dead skin). If the epidermis is renewed too quickly to complete the keratinization, such as psoriasis epidermis renewal only 8 to 10 days, there is flaking (incomplete keratinization).