The sequelae of hyaluronic acid injection at the age of 50 is that there may be subcutaneous bruising, localized pain, hard nodules, allergies and skin infections. After long-term injection of hyaluronic acid, local bleeding or subcutaneous bruising will occur, which is mostly considered to be caused by accidental injury to skin capillaries during injection. Middle-aged people are more prone to subcutaneous bruising as their blood vessels are more fragile. After injecting hyaluronic acid, there will be slight localized skin pain, mainly due to the needle stimulation of local nerves triggered. After injection, localized subcutaneous hardness is found, mostly considered to be caused by hyaluronic acid injection too shallow, usually can recover by itself, if there is discomfort, timely medical treatment to dissolve hyaluronic acid. Localized redness, swelling and itching of the skin after injection is considered to be hyaluronic acid allergy, mostly seen in the sensitive body, at this time should immediately stop injecting hyaluronic acid, timely medical treatment, do not take the initiative to deal with. Long-term skin injection may induce skin infection, mostly due to the aseptic operation is not in place during the injection or the hygiene of the needle eye site after the operation is not well triggered, middle-aged people’s immunity is weaker, it is easier to induce skin infection. If you find the above symptoms aggravated or not cured for a long time after the injection of hyaluronic acid, you should consult the doctor in time and treat under the doctor’s guidance, do not take the liberty to deal with it, so as not to delay the condition. Pay attention to the cleanliness and care of the injection site on weekdays to avoid secondary infection.