Green tea, as a food, does not have the effect of reducing swelling. For double lower limbs and even the whole body and other parts of the edema need to consult a doctor in time. As green tea contains caffeine, which has diuretic effect, it has some effect on swelling. However, the caffeine content in green tea is limited and cannot achieve the therapeutic effect and function, so it cannot reduce swelling. Large amounts of green tea intake, but also easy to stimulate the gastrointestinal tract, leading to digestive discomfort; cause insomnia and so on. General edema is divided into physiological edema and pathological edema. Physiological edema includes premenstrual edema, postural edema, etc. Pathological edema includes pathological edema caused by abnormal cardiac function, renal insufficiency, hepatic insufficiency, and also includes mucous edema caused by hypothyroidism. If edema occurs, patients should go to the hospital in time to find out the cause, do not blindly believe in therapeutic food, affecting the condition and delaying the diagnosis and treatment.