Children’s eyes are swollen in the morning, which may be related to drinking a lot of water or crying before going to bed, and may also be caused by allergic conjunctivitis, nephrogenic edema and other diseases. 1. Drinking a lot of water before going to bed: some children drink a lot of water or cry for a long time before going to bed, which may lead to the children’s eyes appearing swollen in the morning. 2. Allergic conjunctivitis: if allergic children are allergic to bedding such as quilt covers and pillowcases, allergic conjunctivitis may occur, so after waking up, they may have swollen eyes, accompanied by itching and other discomforts. 3. Nephrogenic edema: acute glomerulonephritis and other renal diseases, because of abnormal renal function, fluid retention, children may have swollen eyes. It is recommended that children with obvious swelling of the eyes should consult a doctor in time to assess their condition and follow the doctor’s instructions for treatment.