The Lymphatic System – Facts, Functions & Disorders


How much do you know of your lymphatic system and its role in your body? You might not know much about the system even though it is a central system for your entire health.

What you might not know is that without this 'little known' lymphatic system, your other body systems would cease to function entirely. Follow the conversation to find out why this system is crucial to your wellbeing and health.

But, first things first….

What is the Lymphatic System?

The lymphatic system is a connection of tissues, organs, and vessels for the primary purpose of draining and getting rid of toxins and other wastes in the body tissues and cells. The lymphatic system is part of the immune system and part circulatory system.

While the circulatory system is a closed circuit with the heart being at the center, the lymphatic system is a one-way system. It consists of returning or venous vessels that serve to transport the lymph fluid back to the circulatory system. The journey of the lymphatic vessels ends up at the joint of the two lymph ducts, the thoracic duct, and the right lymph duct.

Various lymphoid organs of the lymphatic system assist the system in its functions, such as in the immune system and the circulatory system. 

The interstitial fluid surrounds the tissue and cells to nourish, lubricate, and cleanse them before leaving the interstitial space through the lymphatic vessels.

The Lymphatic System Procedure

When the blood circulates nutrients and oxygen around the body, it contains blood plasma, which purposely leaks or diffuses through the capillaries' thin walls. The blood plasma then enters the space surrounding the tissue cells.

The area around the body cells is called interstitial space. The blood plasma that leaks from the blood vessels to settle in the interstitial space is called interstitial fluid.

The interstitial fluid surrounds the tissue and cells to nourish, lubricate, and cleanse them. The fluid then leaves the interstitial space through the lymphatic system while changing its name to the lymph.

Lymph is a clear, whitish, or yellowish fluid, where the color varies to the waste protein concentration. It cleans your body cells by carrying away cellular wastes, toxins, dead cells, and other infectious organisms. The lymph from the digestive system carries fats, and it is called chyle. The lymph then enters the lymph nodes

The lymph nodes then filter the lymph fluid to remove all the pathogens, toxins, and any other harmful substance.

If the lymph is excessively laden with infection-causing pathogens, the lymph nodes stimulate excessive lymphocytes to fight and curb the pathogens. A swollen lymph node is as a result of lymphocytes increase signifying severe infection in the area near the lymph node.

As you may know, the blood is pumped by the heart to move through the arteries. Read about the circulation system. The lymphatic fluid, on the other hand, moves by skeletal muscle movement, which squeezes the fluid through the vessels.

After filtration, the lymph fluid then leaves the lymph node through the efferent vessels. The fluid in the vessels enters lymph trunks designated for each part of the body. The four pairs and one unpaired trunk spread around the body's central area.

In the last part of the lymphatic fluids journey through the lymph trunk, the fluid flows to drain into the two lymph ducts where the lymph trunks merge. The lymph fluid then flows on to enter the subclavian veins, both right and left.

Lastly, the fluid enters the bloodstream through the superior vena cava to join the circuit of the circulatory system.

The Lymphatic Structure

The entire journey of the lymph fluid through the lymphatic system involves various lymphoid structures and organs. The structure consists of lymph fluid and lymph vessels. The lymphoid organs are divided into two parts, the primary lymphoid organs and the secondary lymphoid organs.

The Lymph

The lymph is a clear and whitish or yellowish body fluid that originates from interstitial space as interstitial fluid. The blood plasma diffuses into the interstitial space (space between cells) through thin capillary walls. For the right body fluid balance, the interstitial fluid has to leave the interstitial space through the lymphatic system.

The fluid exits the interstitial space carrying body metabolism wastes, organisms, toxins, and cancer cells (if any). Immediately after the fluid starts the journey out of the interstitial space, it ceases to be called interstitial fluid and becomes lymph or lymphatic fluid.

The lymph in the lymph vessels moves by the use of semilunar valves, working together with skeletal muscle pressure and contractions that push the lymph through the vessels. The valves in the vessels prevent the lymph from flowing back, also helping the fluid to continue flowing forward.

Lymphatic Vessels

Lymphatic vessels are other structures in the lymphatic system. They transport lymphatic fluid from interstitial space around your body cells. The small lymphatic vessels are the lymph capillaries which branch from the large vessels.

The tiny lymph capillaries have thin walls with closed ends. The lymph vessels are spread in your entire body except in the bone marrow, the central nervous system, and the non-vascular tissue. From the interstitial space, the lymph capillaries pass on the lymph into the lymphatic vessels. The lymphatic vessels then merge to join lymphatic trunks.

Lymphatic Trunks

Various efferent lymphatic vessels merge into the four pairs of lymphatic trunks and one unpaired lymphatic trunk. All the trunks have names by the areas the lymph nodes serve.

The lymphatic trunks are:

Jugular:  Paired lymphatic trunks of the neck that drain lymph from the cervical lymph nodes.

Subclavia:  Paired subclavian lymphatic trunks that drain to the apical axillary lymph nodes. The left subclavian removes the lymph fluid from your body's left side while the lower part is served by the right subclavian on your body's right side.

Intestinal: The unpaired lymphatic trunk drains chyle from the intestine and the lymph from the stomach, pancreas, spleen, and a portion of the liver.

Bronchomediastinal: The paired lymphatic trunk drain the heart, lungs, trachea, mammary glands, and mediastinal region (containing some part of the esophagus, thymus gland, trachea, and others).

Lumbar: The lower pair of lumbar lymphatic trunks drain the legs, kidneys, and the pelvic region.

The lymphatic trunks then merge to create two lymphatic ducts.

Lymphatic Ducts

The lymphatic ducts are the last stage of your lymph journey in the lymphatic system before entering the circulatory system. The lymphatic ducts drain lymph into the subclavian veins of the circulatory system located in the neck.

Both lumbar lymphatic trunks together with intestinal lymphatic trunk merge to create one much larger lymphatic vessel called cisterna chyli. The lymph vessel then changes its name after reaching the chest region to be called the thoracic duct.

The thoracic duct serves the entire area of your body's left side and the area below the chest. The right side of the paired lymphatic trunks besides lumbar lymphatic trunk drain lymph into the right lymphatic duct. From the lymph ducts, the lymph enters the subclavian veins and, finally, the superior vena cava, which flows into the heart.

Lymphoid Organs

The lymphoid organs are divided into two sections, the primary lymphoid and the secondary lymphoid organs.

Primary Lymphoid Organs

The primary lymphoid organs are the organs that produce lymphocytes and accommodate some to maturity while others migrate to another organ for maturation. The cells in the organs can then mature and become B-cells and T-cells. The two organs are:

Red Bone Marrow

The red bone marrow plays a vital role in the lymphatic system. It generates lymphocytes that eliminate the pathogens in the lymph fluid that drains from the cells. Besides producing the lymphocytes, the red bone marrow also accommodates the B-cells up to maturity.


The thymus is another vital organ of the lymphatic system classified as the primary lymphoid organs. The T-cells generated in the red bone marrow migrate to the thymus for maturation. The thymus provides a conducive environment for T-cells development to maturity, from precursor cells to functional cells.

The secondary lymphoid organ shrinks with age after puberty. In the latter period from puberty, the T-cells production declines. The thymus then begins to shrink and eventually becomes no more in adulthood.

Lymphatic System Functions

The lymphatic system is vital for your body's health by regulating your tissue's pressure, among other functions. Other primary activities of the lymphatic system are:

Balancing Body Fluid

It is the role of your lymphatic system to keep your body fluid balanced. The system removes excess fluid from the body tissues and around the cells to regulate body fluid and pressure. You can refer to your lymphatic system as your body's drainage system.

It drains the fluid in the interstitial space, the spaces between your tissues and body cells. The lymph capillaries remove the interstitial fluid to pass it over to lymphatic vessels, where it changes its name to lymph fluid.

If the lymphatic system fails to remove the fluid efficiently, your body can retain fluid to cause a condition known as edema.

"What is edema?" you may wonder!

Edema is a condition when your body swells due to fluid buildup in the interstitial space.

Fatty Acids Absorption and Fat Transportation

The lymphatic system assists the digestive system in absorbing fats, and fatty acids then transport the digested and emulsified fatty acids into the blood circulation. The lymphatic system absorbs fats through the villi wall to enter into the lacteal.

Lacteals are tiny capillaries of the small intestine serving the lymphatic system in fats absorption. When the fat gets inside the lacteal, they mix with lymphatic fluid to form a milky liquid called chyle. The fluid is then transported into the bloodstream.

Producing Immune Cells

It is the role of the lymphatic system to produce immune cells that form immunity in your body. For instance, the lymphocytes are part of the immune system developed in the bone marrow of the lymphatic system and in the lymph nodes.

Some of the immune cells are monocytes and plasma cells that produce antibodies.

The Secondary Lymphoid Organs (SLO)

This group of secondary lymphoid organs consists of lymph nodes, Peyer's patches, spleen, tonsils, and adenoids.

Lymph Nodes

Lymph nodes or lymph glands are distributed all over your body. They play a significant role in protecting you against infections by destroying infection-causing organisms. When responding to infection, the lymph nodes swell.

Your body has about six hundred lymph nodes that clean the lymph fluid of viruses, bacteria, and any other organism before entering the bloodstream. The lymph nodes are small and oval structures. They are distributed around your body from the head to the knees. 

Some sites of the lymph nodes are deep into the body, such as near the heart and lungs. Others are near the body surfaces, such as the groin and under the arms.

Before the lymph enters the bloodstream, it passes in the lymph nodes for filtration. The role of lymph nodes is to filter the lymph before entering the bloodstream. The lymph nodes contain lymphocytes of white blood cells, which are the immune cells containing B-cells and T-cells.

The lymphocytes then destroy the organisms and infections such as viruses and bacteria coming from the body tissues and cells through the lymphatic fluid.


The spleen, which sits below the ribcage at the left side of the abdomen, is the largest organ in the lymphatic system. This organ is another producer of lymphocyte cells besides the bone marrow and the thymus to support your immune system.

Therefore, the spleen is another organ in the lymphatic system that helps keep you healthy by attacking infection-causing pathogens. The macrophages in the spleen also help the spleen to destroy and consume bacteria, viruses, dead tissue and cells, and other organisms.

Peyer's Patches

Your ileum of the small intestine harbor some small masses of lymphoid follicles spread in the mucous membrane. The masses resemble the lymph nodes. They manage the intestinal bacteria by controlling the growth of infection-causing bacteria and balancing the good bacteria.

Just like other lymph nodes, the Peyer's patches have lymphocytes cells, the B-cells, and the T-cells. The dendritic cells and macrophages also exist in the Peyer's patches. All these help in protecting your intestinal from infections by destroying disease-causing bacteria and other pathogens.


Tonsils are vital organs of the lymphatic system. The tonsils are located at the back of your throat. Many people have a negative notion of tonsils. Some regard tonsils to be of no vital use, while others take them to be a nuisance when they get swollen from reactions.

Both tonsils play their role as lymph nodes, where they filter viruses and bacteria from entering your bloodstream. They also prevent any unwanted object from slipping inside your lungs through the throat.

The tiny organs are useful in both the lymphatic system and the immune system. They produce and contain lymphocytes and antibodies. The organs protect you against respiratory infections such as pneumonia.


The adenoids are a mass of tissues in the lymphatic system that sit inside your mouth's roof or palate at the connection of your nose and throat. Just like the tonsils, the adenoids provide lymphocytes and antibodies to block and destroy infection-causing bacteria and viruses.

The tissues, however, do not last a lifetime. Instead, they begin to shrink at the adolescence stage and continue doing so. By adulthood, they will have shrunk completely.

A Physical Therapist treats a patient who has lymphedema.

Lymphatic System Disorders

The lymphatic system is the drainage system of all wastes from the body cells. The system, therefore, gets direct contact with various harmful bacteria, viruses, and other infection-causing organisms.

Your lymphatic system is prone to get infected or inflamed and even become cancerous.

The most common lymphatic system diseases are:


Lymphadenopathy is a condition of the lymph nodes whereby the nodes swell due to infections in the surrounding tissue. For instance, when the lymph nodes arrest bacteria in the lymph fluid, they produce more lymphocytes and macrophages to attack the bacteria.

The production of excess white cells in the lymph nodes can cause swelling and tenderness to touch, meaning your immune system is healthy and active.

Although you can argue that lymphadenopathy is not a disease but rather a warning of an infection in the peripheral tissue surrounding the lymph nodes, you cannot be far from right.

Lymphadenopathy is a symptom of another health condition such as immunodeficiency disease, lymphoma, or in a worse situation, metastatic cancer.

Despite that, a lymph node affected by lymphadenopathy can not only be swollen but inflamed and painful, making it a condition on its own.


Lymphedema is a condition of excess fluid in interstitial space, causing body swelling.

Your lymphatic system can block due to various reasons such as scarring of lymph nodes or lymph vessels due to injury, infection, or cancer cells. The condition, which is also called lymphatic obstruction, can affect one of your limbs or, in other cases, both of them.

Lymphatic obstruction can occur in other parts of the body as well, such as the genitals. The disease is in the category of chronic diseases, although it is treatable.

Lymphedema is classified as either primary or secondary.

Primary Lymphedema. The primary lymphedema is a condition with a poor performing lymphatic system due to hereditary-caused deformation. The condition is present after birth or develops later in life.

Secondary Lymphedema. Secondary lymphedema is a disorder that you acquire due to some health conditions. The type of lymphedema can be temporal. It means that after dealing with the causing factor, the system can resume normal functioning.

Lymphoma is a malignant condition of the lymphoid cells. Malignancies of lymphatic system cells can either progress slowly or aggressively. Lymphoma is a general term for any cancer affecting one of the lymph nodes, such as adenoids.

What causes lymphoma? The white blood cells or the lymphocytes can proliferate out of control. The cells fail to follow formation signals that control how they grow and hence continue growing nonstop.

The cell formation abnormality can be a genetically influenced cancer, also referred to as a hereditary cancer.

One type of lymphoma is Hodgkin's disease or Hodgkin lymphoma. It is a cancer of the blood which originates from the lymphatic system. Although the cause of the tumor is not known, it has a link to mutations or changes in DNA.

Enlarged Spleen (Splenomegaly)
An enlarged spleen is a hidden condition that can occur without your knowledge. Sometimes, it has to take a doctor to stumble on the disease while on your scheduled medical examinations.

The disease can occur due to various health conditions such as liver disease, a blood disorder, infections, or cancer.

While most cases of the disease are asymptomatic, one significant sign of the disease is persistent pain in the upper abdomen of your left side.

Lymphatic Filariasis (Elephantiasis)
Although not very common, the disease can cause stress, depression, physical pain, and discomfort.

The lymphatic filariasis occurs through mosquito bites, which can infect you with parasitic worms. The worms then can block your lymphatic vessels to cause elephantiasis.

Elephantiasis is common in African and Asian countries or any other country where there are mosquito infestations.

Key Takeaways

A few key points to remember about the lymphatic system are:

The lymphatic system falls between the immune and the circulatory systems. The system develops the immune cells in the bone marrow and the lymph nodes for your immunity. The Lymphatic system is also part of the circulatory system for transporting the lymph fluid.

The system is responsible for balancing fluid by carrying the excess interstitial fluid back to the circulatory system. If the lymphatic system is impaired in any way which can affect its draining role, you risk lymphedema and other complications such as skin or lymph vessel infections.

The circulatory system uses the force of the heartbeat to move blood through its vessels. Your lymph relies on your contribution by muscle activities to flow in its vessels.

Maintaining a healthy lymphatic system is your responsibility to prevent the system's disorders and to keep other body systems functioning. Encourage the proper function of your lymphatic system by incorporating a healthy lifestyle by:

  • Drinking plenty of clean water to dehydrate your body tissues and cells.
  • Eating healthy organic foods rich in nutrients and healthy fats.
  • Exercising regularly to propel lymphatic fluid in a smooth flow through the vessels.
  • Abstaining from unhealthy lifestyle such as being sedentary, smoking, and excessive alcohol use.

Bottom Line

Your lymphatic system plays crucial roles in your body by fighting off bacteria, viruses, fungus, and other pathogens. It is essential to keep yourself hygienically clean to help maintain your good health at all times.

The lymphatic system does not cease from working unless for specific health conditions. Your system would need your support to continue working efficiently and at nonstop.


Now that you have delved deeply into the lymphatic system and learned everything concerning the system, you should respect and cherish all your body systems.

Do you have any concerns about your health and especially your lymphatic system? Arrange for microscopy blood analysis using a high-powered microscope. The examination takes a few minutes to analyze your lymphatic system's health and realize results.

Live Blood Testing

We do Live Blood Analysis and look at dry blood samples specifically.

Lymphatic Congestion

Observed in Layer(s):

White open areas just inside the edge of the sample in a circular or semi-circular pattern. This is associated with stress on the lymphatic system related to acidic deposits, often due to acid-forming foods. May also be associated with water retention or swollen lymph nodes.

Visit Island Healthworks Natural Health Clinic, your Alternative and Holistic Health Service at Nanoose Bay, British Columbia, for your blood analysis. To book your consultation, please call 250-468-7685!

Lymphatic Congestion

If you have any comments or questions, you can address them in the comments section here below or through our email address  

Elizabeth Njuguna is a freelance writer, with a focus on natural health. Her aim is to promote healthy lifestyles through information. Connect with Elizabeth at This email address is being protected from spambots. You need JavaScript enabled to view it.

Editor: Yvonne Dollard Perc
Research Assistant: Elizabeth Njuguna

Designer: Sherry Robb 

Island Healthworks offers in-person and virtual consultations for assessment of your specific needs, with health & lifestyle coaching, featuring the best of integrative natural health care. To book your consultation, please call 250-468-7685!

This article is intended for educational purposes and the information contained within is not intended to treat, diagnose or cure any disease or health problem. Please seek appropriate medical attention for any health complaints. We cannot take responsibility for your health care decisions. Our intent is only to offer health information to help you with your search for better health. 

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Monday, 13 July 2020