Nephritis syndrome usually causes eyelid edema. Nephritis syndrome is mainly characterized by glomerulonephritis, often accompanied by proteinuria, edema, hypertension and/or renal function impairment, etc. According to the onset of acute and progressive nephritis syndrome, it is usually divided into acute nephritis syndrome, acute progressive nephritis syndrome, chronic nephritis syndrome, etc., which is prone to eyelid and facial edema. 1. Acute nephritis syndrome: the most typical case is acute glomerulonephritis after streptococcal infection, and eyelid edema may appear. 2. Acute progressive nephritis syndrome: mainly characterized by progressive worsening of renal impairment over weeks to months. It can be seen in anti-glomerular basement membrane disease, severe lupus nephritis, etc., and often causes eyelid edema. 3. Chronic nephritis syndrome: slow onset, early patients often have no obvious symptoms, or only eyelid edema, fatigue, etc., hematuria and proteinuria delayed or gradually aggravated, but also gradually appear hypertension and/or renal function damage. Patients with nephritis syndrome have decreased glomerular filtration rate, but tubular reabsorption function is basically normal, resulting in glomerulotubular imbalance and decreased filtration rate, which leads to water and sodium retention, making the body water accumulation, which cannot be discharged, and is easy to accumulate in the loose parts of tissues, such as eyelids, face, etc. Therefore, nephritis can cause eyelid edema. It is recommended that patients with nephritis syndrome should go to the hospital in time when edema occurs, and follow the doctor’s instructions to standardize the diagnosis and treatment.