What Is a Lymph Node?

What is a lymph node, and are lymph nodes important? 

Lymph nodes are a vital part of the body’s lymphatic system, which helps fight infection and disease by filtering viruses, bacteria, and other potentially harmful foreign substances. 

Learn how to support a well-functioning lymphatic system and understand what it means when your lymph nodes become swollen or enlarged. 

What is a lymph node?

Lymph nodes are small, bean-shaped glands that are part of the body’s lymph system, which is a key structural and functional component of the immune system. 

The lymphatic system is closely connected to the cardiovascular system and is composed of lymphatic fluid, afferent and efferent lymphatic vessels, lymphatic glands, and lymphatic cells. 

In addition, the spleen and the thymus are also vital parts of the lymph system and the body’s overall immune defense. 

Also referred to as lymph glands, the primary function of lymph nodes is to filter lymph fluid,  which helps trap bacteria, viruses, and other harmful substances before they can spread to vital tissues and organs.

Lymph glands also house white blood cells, a group of specialized immune cells known as lymphocytes, which help detect and destroy pathogenic microbes that can cause infections.

Watch the video below to learn more about the structure and functions of lymph nodes. 

Where lymph nodes are located

Research published in StatPearls indicates that the human body contains approximately 450 lymph nodes, which are located in clusters throughout the body and are connected by a complex network of lymphatic vessels.

Although found in all major body parts, key clusters include the cervical lymph nodes in the head and neck, and the axillary lymph nodes in the underarms, with additional clusters near the chest, abdomen, and groin.

Lymph nodes are generally positioned alongside blood vessels and near critical structures such as the spinal cord, allowing them to efficiently monitor and respond to pathogens.

Once filtered by the lymph nodes, lymph fluid leaves each node through efferent lymphatic vessels, which transport it back into the circulatory system. 

This placement ensures that the immune system can detect and remove infectious microbes and other harmful substances before they affect critical organs. 

What do lymph nodes do?

Lymph nodes play a critical role in the body’s immune defenses and serve several key functions that help protect against infections and disease. 

As lymph fluid enters these nodes, waste products, damaged cells, and potential pathogens are filtered and then monitored and processed by specialized immune cells. 

Inside each lymph node, immune cells trap foreign particles, invading microbes, and even cancer cells, and present them to lymphocytes, which triggers a targeted immune response against these potential threats.

By facilitating this process, lymph nodes help prevent the spread of infection and maintain overall immune surveillance.

Lymph nodes also play a key role in removing cellular debris and damaged cells, supporting the body’s repair and recovery processes, and promoting healing and overall well-being. 

In addition, the lymphatic system helps maintain the body’s fluid balance by transporting excess fluid through lymph vessels back into the bloodstream. This helps minimize tissue swelling and edema, as well as supports circulatory health and blood pressure control. 

Common causes of swollen lymph nodes

When immune cells, such as dendritic cells, detect foreign invaders, they trap and transport them to the nearest lymph node to activate lymphocytes and trigger an immune response. This process can lead to lymph node swelling, also known as lymphadenopathy or swollen glands.

Common causes of swollen lymph nodes include:

• Bacterial infection
• Viral infection 
• Fungal or parasitic infection 
• Autoimmune disorders 
• Localized inflammation or injury near a lymph node region

Certain medicines that can trigger the body’s immune system, such as antiseizure drugs, antibiotics, or vaccines, can also affect lymph nodes and cause swelling.

Many cases of enlarged lymph nodes are due to infections or immune activity and resolve within a few days. 

However, persistent or progressively enlarging nodes may indicate a more serious condition, such as a type of blood cancer called lymphoma, which can cause swollen lymph nodes throughout the body.

How to support healthy lymph nodes

Maintaining healthy lymph nodes involves supporting a well-functioning immune system, minimizing exposure to harmful substances, and stimulating proper lymph drainage. 

Here are five steps you can take to promote a healthy lymphatic system. 

1. Stay physically active

Unlike the cardiovascular system, which relies on the heart as a pump, the movement of lymphatic fluid is driven by body movement and muscle contraction. 

Avoiding long periods of sedentary activity and engaging in regular physical activity, such as walking, stretching, or swimming, keeps lymph fluid circulating. This helps prevent stagnation and supports detoxification through the lymph nodes.

Evidence published in Frontiers in Cardiovascular Medicine examined the role of exercise in preserving lymphatic function.

The authors concluded, “Exercise that stimulates muscle contraction can promote lymphatic flow, and potentially decrease fluid accumulation in tissues.”

2. Focus on an anti-inflammatory diet 

Avoiding processed foods, added sugars, and refined carbohydrates, while prioritizing a nutrient-dense anti-inflammatory diet, supports healthy lymph nodes by reducing strain on the immune system.

“Supporting the body’s ability to maintain balanced immune and inflammatory responses helps lymph nodes filter fluid and waste more efficiently,” explains Dr. Berg. “This plays a crucial role in supporting a well-working lymphatic system.”

Healthy Keto® is an ideal dietary approach to support lymph node functions as it emphasizes minimally processed and nutritious whole foods rich in anti-inflammatory nutrients. 

This advanced version of the ketogenic diet advocated high-quality proteins, pasture-raised eggs, wild-caught fish and game meat, organic vegetables, and full-fat dairy. 

A study published in the Journal of Human Nutrition and Dietetics confirms the benefits of a ketogenic diet for lymphatic function and highlights its therapeutic potential in reducing swelling associated with lymph fluid accumulation. 

3. Consume zinc-rich foods

Regularly consuming a variety of zinc-rich foods is essential for immune protection, as zinc supports the development, activation, and function of lymphocytes and other critical immune cells. 

Optimally functioning immune cells are crucial for lymph node health, as they allow the nodes to efficiently filter pathogens, waste, and damaged cells, helping maintain a responsive and balanced lymphatic system.

Some of the best dietary sources of zinc include oysters, shellfish, beef liver, lamb, egg yolks, and pumpkin seeds.

4. Limit exposure to toxins                        

Because lymph nodes are the first line of defense against invading microbes and other harmful substances, it’s crucial to reduce the body’s toxic burden. 

Limiting exposure to chemicals, pesticides, heavy metals, and environmental pollutants whenever possible helps reduce stress on the lymphatic system and lymph nodes. 

Therefore, it’s recommended to choose organic produce whenever possible to minimize pesticide intake.

In addition, it’s beneficial to use water and air filters and choose natural, non-toxic household products, while avoiding smoking and excessive alcohol, all of which help reduce toxin exposure.

5. Stimulate lymph drainage

Stimulating lymph drainage helps keep lymph fluid moving, reduces lymph fluid congestion, and supports healthy lymph node function.

Staying hydrated and supporting the body’s fluid balance is vital for optimal lymph movement and efficient removal of waste and excess fluid from tissues, which helps maintain a healthy, responsive lymphatic system.

Other ways to naturally promote lymph drainage include:

• Physical exercise 
• Deep diaphragmatic breathing 
• Gentle massages
• Dry brushing
• Compression clothing  

When to talk to your doctor

It’s crucial to consult a doctor if you notice persistently swollen lymph nodes or enlarged lymph glands that are accompanied by other symptoms such as unexplained weight loss, night sweats, fever, or fatigue.

A healthcare provider will likely perform a physical examination and recommend a blood test or imaging to check for injuries or infections that may be causing the swollen lymph glands.

If your doctor is concerned about lymphoma, a form of cancer affecting the lymphatic system,  further evaluation may be needed, which could include removing lymph nodes for testing or cancer surgery as part of treatment. 

FAQ

Sources

1. https://www.ncbi.nlm.nih.gov/books/NBK557833/ 
2. https://pmc.ncbi.nlm.nih.gov/articles/PMC10126351/ 
3. https://pubmed.ncbi.nlm.nih.gov/38837503/