Sudden swelling of the patient’s lower eyelid may be caused by eye infections, eye allergies, eye trauma. Systemic systemic diseases can also lead to swelling of the patient’s eyes, but usually slowly rather than suddenly appearing eye swelling. 1. Eye inflammation: Infectious keratitis, conjunctivitis and other eye infections in patients, under the stimulation of inflammation, can lead to conjunctival congestion and edema, can also be accompanied by photophobia, tearing, eyelid swelling and other uncomfortable symptoms. 2. Eye allergy: If allergic patients are exposed to allergens such as pollen, dust, animal hair, it can trigger a systemic allergic reaction, which can lead to eyelid swelling, accompanied by itchy eyes and other uncomfortable symptoms. 3. Eye trauma: eye trauma patients are subjected to extrusion or impact, eye swelling can occur, can also be accompanied by eye pain, subcutaneous bruising and other symptoms. In addition, systemic diseases such as liver and kidney function damage, diabetic peripheral neuropathy, heart failure, etc. can also lead to eye swelling, but usually slowly, usually not suddenly appear eye swelling. Patients with significant eye swelling are advised to seek prompt medical attention to assess their condition and follow the doctor’s instructions for treatment.