Single kidney and the presence of foot edema, generally need to consider local reflux obstruction or local edema caused by renal disease. 1. Local reflux disorder: when people with only a single kidney have varicose veins or local thrombosis in the lower limbs, it will cause vascular obstruction, which leads to fluid reflux disorder, and may stimulate the swelling of the feet or edema of the lower limbs. For this type of edema, vasodilator or thrombolytic therapy is generally recommended to effectively remove the symptoms of vascular obstruction or stenosis, thus helping to treat edema. 2. Kidney disease: If a single kidney is damaged to different degrees in the process of work and body circulation, which leads to abnormal water reabsorption and metabolism, proteinuria and hypoproteinemia will be triggered, thus stimulating different degrees of edema in the lower limbs. The treatment of nephropathic edema requires targeted treatment for renal damage, and can also promote fluid metabolism by taking diuretics such as furosemide, bumetanide, and so on. People with single kidney should go to the hospital for lower limb vein and kidney examination immediately after the appearance of foot edema, and choose the appropriate medication under the guidance of the doctor, do not self-medication.