When a pregnant woman in her fifth month presents with edema, especially with edema of both lower extremities or eyelids, and this edema is symmetrical, kidney disease and edema due to pregnancy need to be considered. If kidney disease is considered, urine albumin and blood albumin need to be tested. If albumin in the urine and albumin in the blood are decreased, and the lipids or blood biochemistry are similarly abnormal, it is necessary to consider whether kidney damage existed before pregnancy without being aware of it, and this damage was aggravated after pregnancy. If the condition occurs after 20 weeks, it is necessary to consider whether it is pre-eclampsia, which, in addition to edema and protein in the urine, may also have elevated blood pressure. If pre-eclampsia is considered, it needs to be treated aggressively by the obstetrician to prevent serious effects on the baby. If unilateral limb edema occurs after the fifth month of pregnancy, it is considered to be caused by local factors, and appropriate examination is needed.