Lymphatic System: Facts, Functions i Diseases


Human body contains hundreds of lymph nodes. According to American Cancer Society some of these nodes are positioned deep in the body as around heart and lungs and some are closer to the surface as under arms or groin.

According to the U.S. National Library of Medicine (NLM) the largest lymphatic organ is the spleen which is located above the kidneys on the left side of the body. This organ helps in the fight against infections and also controls the number of red blood cells and blood storage in the body. If the body is attacked by bacteria, viruses or other microorganisms, then the lymphatic nodes and the blood increase the amount of white blood cells (lymphocytes) which will attack the invaders. The white blood cells’ function is to produce antibodies to attack and destroy the invaders and prevent the infection to spread. People who have lost the spleen due to disease or injury can live without it but are more prone to infections.

Lymphatic System Facts, Functions i Diseases

According to Merck Manual the thymus which is located in the chest above the heart is a small organ which stores immature lymphocytes (specialized white blood cells)and helps in making them active T cells- cells which fight against infected and cancerous cells.

Tonsils are large group of lymphatic nodes located in the pharynx. American Academy of Otolaryngology considers them as “first line of defense as part of the immune system”.  Bacteria and viruses enter the body through the nose and mouth.

The word “lymph” has Latin origin, from the Latin word lympha, which means “connected to water” Lymph is colorless and clear fluid.

Once the plasma brings the nutrients and removes the waste from the cells, it leaves them. Most of this fluid goes back in the blood flow through small blood vessels known as venules and goes on as venous blood. According to the Mayo Clinic, the rest of the fluid turns into lymph.

Diseases and disorders of the lymphatic system

Immunologists are the ones that deal with diseases and disorders of the lymphatic system. Dermatologists, physiatrists, vascular surgeons and oncologists are also involved in healing of different lymphatic disorders and lymphedema therapist is specialized in manual drainage of the lymphatic system.

According to Dr. James Hamrick, chief of medical oncology and hematology at Kaiser Permanente in Atlanta, the most common lymphatic system disorders are lymph nodes enlargement or lymphadenopathy, lymphatic obstruction and cancer on the lymphatic system.

After bacteria appear in the lymph fluid, more white blood cells are produced to fight the infection and thus sometimes swelling appears. According to NLM swollen nodes can also appear on the neck, groin and armpits.

Cancer, inflammation and infection can be the cause of Lymphadenopathy. It is caused by infections as: locally infected skin wounds, bacterial infections such as strep throat or viral infections such as mononucleosis or HIV infection- claimed Hamrick. “The enlargement of the lymph nodes may be localized to the area of infection, as in strep throat, or more generalized as in HIV infection.”

When the person’s immune system is weak, autoimmune or inflammatory conditions occur and can cause enlargement of lymph nodes. According to Hamrick medical condition as lupus can appear as well.

Cancer of the lymph nodes is known as Lymphoma and occurs due to uncontrollable growth and multiplying of lymphocytes. According to Dr. Jeffrey P. Sharman, director of research at Willamette Valley Cancer Institute and medical director of hematology research for the U.S. Oncology Network there are various types of lymphoma.

 “The first ‘branch point’ is the difference between Hodgkin lymphoma and non-Hodgkin lymphoma (NHL),” Sharman said. More common is Non-Hodgkin lymphoma, according to the Lymphoma Research Foundation.

Hamrick also noted that if the patient had a surgery or radiation therapy against cancer, the lymphatic flow goes back in the heart and causes swelling known as lymphedema. This mostly occurs in women with breast cancer and had surgery to remove it. With this operation lymph nodes in the armpit are removed as well.

Hamrick claims that the more lymph nodes are removed the greater is the risk of chronic swelling and pain caused by lymphedema in the arm.  “Fortunately modern surgical techniques are allowing for fewer lymph nodes to be removed and thus fewer cases of severe lymphedema for breast cancer survivors.”

According to the Castleman Disease Cooperative Network Castleman the disease represents several inflammatory conditions which cause enlarged lymph nodes and can cause dysfunction of some organs. This medical condition is not cancer but is very similar and is usually treated with chemotherapy. It can affect one lymph node (unicentric) or several lymph nodes (multicentric).

According to the Lymphangiomatosis & Gorham’s Disease Alliance the disease which causes numerous cysts or lesions made by lymphatic vessels is called Lymphangiomatosis and this disease is linked with genetic mutation.

Diagnosis and treatment

Hamrick stated that lymphatic system diseases are often diagnosed when lymph nodes become swollen and are large enough to be felt (“palpable lymphadenopathy”) or seen on CT scans or MRIs.

Most of enlarged lymph nodes are not alarming because in this way the organism is fighting against various infections as upper respiratory infection caused by virus. But in case when lymph nods are too large and last longer than the infection than it is time to pay more attention. There is no exact size but if they are persistent and larger than one centimeter can be dangerous and require doctor’s attention.

According to Stephanie Bernik chief of surgical oncology at Lenox Hill Hospital in New York, usual symptoms of every lymphatic disorder are fever, swelling of the arm or groin, night sweats and weight loss. “A PET or CAT scan is usually ordered to further investigate.”

The location of the lymph nodes together with other symptoms that the patient has, is crucial for the diagnosis of lymphadenopathy. If infection is the cause than the lymph nodes are observed until the infection is gone. But if they are growing quickly without any obvious infection, than biopsy is required for the doctor to determine whether they are cancerous or an infection.

The biopsy sometimes needs to be performed by a surgeon in operating room. In this way the tissue can be obtained for better diagnosis.

According to Sharman, there are various, specific treatments for many types of leukemia and lymphoma.  “There is no one ‘summary’ of treatment options. Treatment options can include traditional chemotherapy, immunotherapy (such as using antibodies or immune modulating drugs), and even radiation.”