Hyaluronic acid, with its unique molecular structure and physical and chemical properties, has many important physiological functions in vivo, such as lubricating joints, regulating the permeability of blood vessel walls, regulating the diffusion and operation of protein, water and electrolytes, and promoting wound healing. More importantly, hyaluronic acid has a special water retention function and is the best moisturizing substance found in nature at present. Known as the ideal natural moisturizing factor. Hyaluronic acid is the main component of connective tissues such as interstitial tissue, vitreous body and synovial fluid, and has important physiological functions in water retention, extracellular space maintenance, osmotic pressure regulation, lubrication and cell repair. Hyaluronic acid molecules contain a large number of carboxyl and hydroxyl groups, which are in water; Intramolecular and intermolecular hydrogen bonds are formed in the solution, which makes it have strong water retention effect and can bind more than 400 times of its own water; At a higher concentration, its aqueous solution has obvious viscoelasticity because of the complex three-level network structure formed by intermolecular interaction. Hyaluronic acid, as the main component of intercellular matrix, directly participates in the regulation of electrolyte communication inside and outside cells, and plays a role as a filter for physical and molecular information. Macromolecule hyaluronic acid can inhibit cell migration, proliferation, differentiation and phagocytosis, while small molecule hyaluronic acid can promote cell migration, proliferation, differentiation and phagocytosis. Hyaluronic acid has unique physical and chemical properties and physiological functions, and is widely used in medicine. Hyaluronic acid can be used as viscoelastic agent in ophthalmic intraocular lens implantation and filler in joint surgery such as osteoarthritis and rheumatoid arthritis. As a medium, it is widely used in eye drops, and also used to prevent postoperative adhesion and promote skin wound healing. The complex formed by the reaction of hyaluronic acid with other drugs has a sustained release effect on drugs, which can achieve the purpose of directional and timed release. With the development of medical science and technology, the application of hyaluronic acid in medicine will be more and more extensive. The side effects of hyaluronic acid occasionally cause urticaria and itching, so stop taking the medicine and handle it properly. Sometimes there is pain and swelling, and occasionally there is edema, redness, heat sensation and local pressure. Precautions for hyaluronic acid: Hyaluronic acid should be treated aseptically, limited to 1 time, and it is forbidden to use after the Perfectha hyaluronic acid gel is damaged. It is not suitable to inject when the joint inflammation is obvious, and then inject Perfectha hyaluronic acid gel after the inflammation is eliminated. When joint effusion occurs, puncture and drainage should be done as appropriate. Perfectha hyaluronic acid gel will cause pain if it leaks out of the joint cavity, so it must be injected into the joint cavity. Sometimes it will cause pain, and it will be quietly treated locally after injection of Perfectha hyaluronic acid gel. Hyaluronic acid will precipitate when it meets disinfectants such as benzalkonium chloride and quaternary ammonium salt. , so we should pay full attention to it when using it. Pregnant women and lactating women should use it with caution, those with impaired liver function should use it with caution, and those who are allergic to Perfectha hyaluronic acid gel should use it with caution. Precautions before hyaluronic acid injection: 1, and make full psychological preparation. You can choose a trusted medical unit or doctor for surgery, eliminate the fear of hyaluronic acid injection, be full of determination and security, be calm and cooperate with the doctor automatically, and realize a bright hope. Don't blindly go to the doctor to inject hyaluronic acid, so as not to produce bad results. 2. Before hyaluronic acid injection, you should fully understand relevant knowledge and reflect on relevant books. It is best to visit people who have already done hyaluronic acid injection, and it is best to see the whole process of hyaluronic acid injection. 3. Before injecting hyaluronic acid, there should be no bacterial lesions at the injection site, such as folliculitis, furuncle, acne, acute ophthalmia, sinusitis, rhinitis, nasal vestibular furuncle, etc. 4. It is best to take a bath the day before hyaluronic acid injection. On the day of injection of hyaluronic acid, the dirt and grease on the face should be washed off with soap before going to the operating table to increase the number of bacteria as much as possible. Before hyaluronic acid injection, there were other diseases in the body, which constituted low resistance, and also caused hyaluronic acid injection infection at will, affecting wound healing. 5, women can not do hyaluronic acid injection during menstruation, so as not to constitute postoperative infection.