Lymph, also known as lymphatic fluid, is a colorless, transparent fluid in the body. Lymph fluid forms in the capillary lymphatic vessels and then flows into the collecting lymphatic vessels and finally into the veins to enter the blood circulation. Lymph fluid first enters the capillary lymphatic vessels, which then form a network of lymphatic vessels and finally converge to form the collecting lymphatic vessels. All lymphatic vessels converge to form the two largest lymphatic conduits in the whole body, i.e., the left thoracic conduit and the right right lymphatic conduit, which enter the left and right subclavian veins respectively, completing the process of lymphatic circulation from tissues to blood. An important feature of the lymphatic circulation is that it flows in one direction without forming a true circulation. The lymphatic circulatory system is an important auxiliary system for the return of tissue fluids to the blood circulation, and the lymphatic circulation is physiologically important for maintaining the normal life activities of the organism. For specific knowledge, consult a specialist.