Legs will become thicker in the afternoon section considered as: lower extremity artery disease, common in lower extremity thrombo-occlusive vasculitis, Raynaud’s syndrome, etc., when the arterial blood flow is slowed down, so that local hypoxia causes blood extravasation, resulting in lower extremity edema, legs will become thicker. It may also be venous disease, common lower limb saphenous varicose vein, small saphenous varicose vein, venous reflux obstruction, causing fluid hydrostatic pressure elevation, bilateral lower limbs obvious edema, can be manifested as lower limb varicose veins, serious can have skin ulcer formation. It may also be cirrhosis, heart failure, and hypoproteinemia, which often cause slowed blood flow and hypoproteinemia causing extravasation of water, thus causing lower limb edema.