The eyelid swelling of one eye in the morning may be caused by nephritis, conjunctivitis, fatigue, etc. The following is a specific analysis: 1. The eyelid swelling of one eye in the morning may be acute glomerulonephritis, acute glomerulonephritis may lead to eyelid swelling. The reason for this is the reaction of antigens and antibodies to form immune complexes that settle on the surface of the kidney and form inflammation. The patient with acute glomerulonephritis will have a glomerular imbalance, a decrease in glomerular filtration rate, and a rise in tubular reabsorption capacity will cause water and sodium retention, so eyelid swelling will occur. 2. fatigue, if the patient stays up late at night watching cell phones, TV, etc. resulting in excessive eye fatigue, eyelid swelling can also occur. 3. inflammation, if the patient’s conjunctiva is inflamed can lead to eyelid redness, swelling and pain.