Lower limb edema for a few days and disappeared may be kidney disease (such as glomerulonephritis, nephrotic syndrome, etc.), may also be varicose veins of the lower limbs and other conditions, need to be specifically analyzed. 1. Kidney disease: kidney disease such as glomerulonephritis, nephrotic syndrome, etc., will appear due to the decline in glomerular filtration rate or proteinuria, but after the condition is relieved, the edema of the lower limbs may disappear, urine routine, biochemistry, and other tests can be used to assist in the definitive diagnosis. 2. Varicose veins of the lower limbs: when varicose veins of the lower limbs, edema may appear because of the obstacle of blood circulation in both lower limbs, and it can be improved after resting or elevating the lower limbs, and ultrasonography of the blood vessels of the lower limbs can assist in the clear diagnosis. There are many causes of lower extremity edema, it is recommended to consult a doctor in time to avoid delaying the condition.