Lymphatic reflux is the process by which the lymphatic fluid in the body passes through the lymphatic vessels, lymph nodes, and finally remits to the blood circulatory system. The circulatory system of human body has two parts, one is the blood circulatory system and the other is the lymphatic circulatory system. The lymphatic circulation system, in which the lymphatic fluid mainly comes from the tissue fluid, which comes from the plasma components in the oozing capillaries, and these tissue fluids are mixed into the capillary lymphatic vessels to become lymphatic fluid, which then gradually converges to the thicker lymphatic vessels, and after filtering by the lymph nodes, it finally reverts to the upper and lower vena cava and reverts to the blood circulation. Lymphatic reflux can bring back the part of plasma and protein leaked from the blood circulation to the blood circulation system, which is a powerful supplement to the blood circulation system. When inflammation occurs in lymphatic vessels or lymph nodes, or when lymph nodes become enlarged due to tumors, lymphatic return is impaired and swelling of the limbs may occur.