Red and swollen eyelids may be caused by physiological reasons or blepharitis, soft tissue contusion, conjunctivitis and so on. 1. Physiological reasons: If the patient does not sleep well, sleeps with a pillow too low, or drinks too much water before going to bed, it may have an impact on the blood return to the face, causing red and swollen eyelids, which usually does not require special treatment and can be relieved after rest. 2. Blepharitis: If the patient does not pay attention to eye hygiene or if the patient’s resistance decreases, it may cause bacterial infection of the eyelid glands and induce blepharitis, and the patient may have red and swollen eyelids, accompanied by pain, tearing and other uncomfortable symptoms. 3. Soft tissue contusion: When the patient’s eyelid is hit or bruised, it is easy to cause soft tissue contusion, and the patient may have a red and swollen eyelid, and may also have localized bruising. 4. Conjunctivitis: The conjunctiva is an important tissue in the eye, when the patient’s conjunctival tissue is infected by bacteria or viruses, conjunctival inflammation may occur, resulting in redness and swelling of the eyelids and other symptoms, which may be accompanied by eye pain, tearing and other symptoms. It is recommended that patients with significant redness and swelling of the eyelids seek prompt medical attention to evaluate their condition and follow medical advice.