Swelling under the patient’s eyes may be caused by trauma, tumor, infection, mosquito bites, skin allergies and so on. 1. Trauma: If the patient suffers from external impact, extrusion, fall, car accident, etc., it may lead to congestion and swelling of the skin and soft tissues under the eyes of the patient, thus causing swelling under the eyes of the patient. 2. Tumor: if the patient’s eyelid localized lipoma or osteoma and other occupying diseases, it will also appear swelling under the eyes. 3. Infection: if the patient has folliculitis or soft tissue infection under the eyes, under the stimulation of inflammation, the swelling under the eyes will also appear. 4. Mosquito bites: If the patient’s local skin is bitten by mosquitoes, swelling under the eyes can also occur. It is recommended that patients with significant swelling under the eyes should consult a doctor in time to assess their condition and follow the doctor’s instructions for treatment.