The occurrence of acne is closely related to factors such as excessive sebum production, blockage of hair follicle sebaceous ducts, bacterial infection and inflammatory reactions. After puberty, the level of androgens in the body, especially testosterone, rises rapidly, promoting the development of sebaceous glands and producing large amounts of sebum. At the same time, abnormal keratinization of the hair follicle sebaceous gland ducts causes duct blockage, resulting in obstruction of sebum drainage and formation of keratin plugs or microcomedones. A variety of microorganisms, especially Propionibacterium acnes, proliferate in the hair follicles. The lipase produced by Propionibacterium acnes breaks down sebum to produce free fatty acids and chemotactic inflammatory cells and mediators, ultimately inducing and aggravating inflammatory reactions. The lesions tend to occur on the face and upper chest and back. The non-inflammatory lesions of acne manifest as open and closed pimples. The typical lesion of closed acne (also known as whiteheads) is a skin-colored papule about 1 mm in size with no visible follicular opening. Open pimples (also known as blackheads) appear as dome-shaped papules with significantly dilated follicular openings. Further development of acne can lead to a variety of inflammatory lesions that manifest as inflammatory papules, pustules, nodules, and cysts. Inflammatory papules are red in color and range from 1-5 mm in diameter; pustules are uniform in size and filled with white pus; nodules are larger than 5 mm in diameter and are hard and painful to touch; and cysts are deeper in location and filled with a mixture of pus and blood. These lesions may also fuse to form large inflammatory plaques and sinus tracts, etc. Inflammatory lesions often leave behind hyperpigmentation, persistent erythema, and depressed or hypertrophic scarring after they have resolved. Clinically, acne is classified into 3 or 4 grades according to the nature and severity of acne lesions: Grade 1 (mild): acne only; Grade 2 (moderate): in addition to acne, there are some inflammatory papules; Grade 3 (moderate): in addition to acne, there are more inflammatory papules or pustules; Grade 4 (severe): in addition to acne, inflammatory papules and pustules, there are also nodules, cysts or keloids. Precautions 1. Cleansing: Keep the skin clean, wash the face with warm water, avoid using alkaline soap, and do not use cosmetics with a lot of oil and irritation, so as not to further fill the hair follicles and aggravate acne. For patients with greasy skin, alternate between using neutral alkaline soap in the morning and before going to bed and washing the face with a facial cleanser suitable for oily skin only, and gently massage with the fingertips of both hands in the direction of the skin line for 3-5 minutes to enhance the decontamination power of the soap and cleanser, then wash with warm or lukewarm water to thoroughly remove the dust and oil and dirt from the skin that day. If there is more facial dust and grease, you should rinse with warm water in time. The general number of times to wash the face 2-3 times a day is appropriate. 2, wash your hair: people with oily skin should also wash their hair regularly, because the oiliness of the scalp is also prone to cause acne where the hair meets the face. 3, careful use of cosmetics: avoid using oily or powder cosmetics, use water quality care products as appropriate, especially avoid heavy makeup. Before going to bed, you should thoroughly remove the day’s cosmetics, and avoid applying nutritional creams and ointments before going to bed, so that the skin at night is easy, unobstructed and fully breathes. If there is already acne on the face, we should avoid using foundation, cosmetics, some people want to cover up with foundation, which in turn causes the opposite effect. 4, bedding: do not neglect the pillowcase, pillowcase cleanliness and hygiene. Pillow towel should be changed once a day or two, the pillowcase should be changed and washed once a week. Pillow towel often in contact with the skin of the face, if you wash your face without changing the pillow towel is equivalent to not washing your face. Pillowcase because of direct contact with the face, easy to get on mites, dust, dandruff and other dirty things, regular change is very necessary. 5, avoid scratching, squeezing: avoid using your hands to touch the acne that has grown or use your hair and foundation cream to cover the rash, especially to overcome the bad habit of squeezing and pressing the acne with your hands, because the bacteria on your hands and the spoils on your hair can easily infect your skin and aggravate the acne, while squeezing and pressing can cause permanent depression scars, leaving lifelong regrets. 6, sun protection: face has acne should also pay attention to sun protection, try not to sun, some people think that the face will be black can hide the red spots on the face, in fact, it will not only cover up will have the opposite effect, is to make acne worse, such as at the beach or swimming, not only strong ultraviolet rays, pool water for acne skin is also a major stimulus. 7, pay attention to diet: usually eat more food rich in vitamin A/C/F and fiber (such as vegetables, fruits), clean diet, less sweets and greasy food, less ginger, garlic, chili, less drinking strong tea, coffee and other stimulating food and drinks, do not smoke, do not drink, keep the bowels open. Frequent constipation can be used mung beans 20 grams, 50 grams of wise rice, cooked into a porridge, add a small amount of rock sugar and blend, twice a day. 8, sports and exercise: adhere to do some large indoor exercise to accelerate blood circulation, to promote the timely discharge of body waste, so that the skin in the process of continuous sweating to keep the pores open, followed by timely cleaning. Develop the habit of daily exercise, moderate exercise can promote metabolism, for the body and skin have a good effect, but do not 5 minutes of heat, to be persistent, remember, even 3 minutes of gymnastics every day, is the secret to maintaining beautiful skin. 9, do not stay up late: often stay up late for the skin also has a lot of damage, the skin’s metabolism is usually carried out from 11:00 p.m. to 2:00 midnight, good and sufficient sleep, can make the skin by the perfect maintenance. 10, mental: mental stress can cause sebum secretion, is also one of the reasons for long acne, should do more to make their mood happy things, lifting the daily work or academic pressure. Avoid emotional anxiety and tension, maintain an optimistic and happy mood, and realize that this is a temporary physiological phenomenon.