The lymph nodes are small rounded organs scattered throughout the body in the path of lymphatic circulation. They form small bulges where a large amount of lymph can accumulate. Lymph is a biological fluid that contains many cells involved in defending the body, including leukocytes, or white blood cells. Thus, the main function of the lymph nodes is to ensure the immune defense of the body, mainly by producing antibodies, in case of recognition of a foreign element, and releasing them into the bloodstream. Usually measuring not more than one centimeter in diameter, the numerous nodes in the human body can grow under the effects of various diseases and more or less severe infections.