Hyaluronic acid injections are now a regular part of the micropigmentation industry and can be used for everything from skin care to facial contouring. Although hyaluronic acid, or sodium hyaluronate, exists in the human body itself, injectable hyaluronic acid is always a foreign substance. At the same time, any procedure has its risks and complications, and even compliant medications can have certain side effects. In the case of hyaluronic acid, the following side effects may occur after facial injections: 1. Excessive injections may lead to obvious facial swelling, stiff expression and unevenness; 2. If unprofessional and unqualified doctors are chosen to perform the injections, the facial nerves as well as the blood vessels may be touched during the injections, leading to ocular embolism, intracranial embolism, facial paralysis, and in severe cases, blindness or even death; 3, After injection, patients may have redness, swelling, heat, pain, etc., which can gradually subside, if it still does not subside after a longer period of time, they should go to the hospital in time for examination and treatment. Therefore, when injecting hyaluronic acid, candidates must bear in mind the principle of appropriate amount, and choose regular institutions as well as professional doctors to minimize the risk of injection.