Children with bags under the eyes may be caused by acute glomerulonephritis, drinking water before bedtime and genetic factors. 1. Acute glomerulonephritis: also known as acute nephritis. Due to a variety of bacteria, or viruses lead to infection of the human body, causing a series of immune responses, the body produces immune substances, will lead to acute inflammatory injury of the glomerulus, the symptoms of children with bags under the eyes, accompanied by edema and hematuria symptoms. 2. Drinking water before going to bed: As children drink too much water before going to bed at night, there will be the phenomenon of bags under the eyes, accompanied by facial swelling and other phenomena. It is recommended to avoid drinking too much water before going to bed. 3. Genetic factors: do not rule out genetic factors, both parents have bags under the eyes, the child may inherit the parents’ genes, the phenomenon of bags under the eyes. When the child has bags under the eyes, it is recommended that parents take the child to the hospital for examination and diagnosis in a timely manner, and after clarifying the cause of the disease, treatment will be carried out under the guidance of the doctor.