The patient’s eyelid redness, swelling, itching, may be related to physiological factors, but also may be blepharitis, allergic conjunctivitis, blepharitis and other causes. 1. Physiological factors: commonly found in mosquito bites, if the eyelid area is bitten by mosquitoes, it is easy to make mosquitoes retain toxins in the skin of the bite, which may cause eyelid redness, swelling and itching. 2. Blepharitis: If the patient has poor eye hygiene habits or wears contact lenses for a long time, eye infections such as blepharitis may occur, and the patient may have red, swollen and itchy eyelids, accompanied by a foreign body sensation in the eyes, pain and other manifestations. 3. Allergic conjunctivitis: After contact with cosmetics, pollen, dust mites and other allergens, allergic reactions can lead to eyelid redness, swelling, itching and other symptoms. It is recommended that patients with red, swollen and itchy eyelids should consult a doctor in time to assess their condition and follow the doctor’s instructions for treatment.