Skin redness and swelling may be caused by trauma, insect bite reaction, contact dermatitis, etc. It can be treated by physical therapy, application of medication as well as oral medication. 1. Trauma: If the patient is hit by trauma, it will easily lead to the rupture of capillaries under the skin, resulting in bleeding and swelling. First of all, use an ice bag to apply cold compresses to the swollen parts of the skin to promote capillary contraction and reduce bleeding, and then take a hot towel to apply hot compresses to the local area after 24 hours to promote blood circulation and improve the phenomenon of redness and swelling of the skin. 2. Insect bite reaction: insect bite reaction refers to the human body by the insect bite produced by the allergic reaction, mosquitoes bite the skin saliva into the human body will produce some perverse reactions, easy to lead to swelling of the skin as well as pain, itching symptoms. You can apply dexamethasone acetate cream, droned cream and other medications under the guidance of a doctor, which can play an anti-inflammatory role and reduce swelling. 3. Contact dermatitis: If the patient uses irritating and allergic substances, it will easily lead to skin mucous membrane damage, which will cause skin erythema and mild edema. You can apply glycerine lotion, tacrolimus ointment and other drugs under the guidance of the doctor for treatment, while taking oral antihistamines, such as loratadine tablets, chlorpheniramine maleate tablets and so on. Swollen skin may also be caused by kidney disease, heart disease and other diseases, patients need to consult a doctor to clarify the cause of the disease, follow the doctor’s instructions standardized treatment, do not self-medication.