What are lymph nodes?
Lymph nodes are small, bean-shaped organs that filter substances in your body. Cells that help fight infections make up your lymph nodes along with lymph tissue. There are hundreds of lymph nodes throughout your body. The most well-known places where you’ll find lymph nodes are in your armpits, neck and groin.
What do lymph nodes do?
A lymph node’s job is to filter substances in your lymph fluid, which is a collection of fluid that drains from your cells and tissues. Lymph fluid contains:
- White blood cells (lymphocytes).
- Damaged cells.
- Cancer cells.
- Bacteria and/or viruses (foreign invaders).
Lymph fluid flows through the tissue that makes up lymph nodes, where the tissue filters and recycles lymph fluid that your body needs. The cells within your lymph nodes will attack, destroy and eliminate waste, especially foreign invaders, to help your immune system keep you healthy.
How do lymph nodes help with other body systems?
Your lymph nodes work closely with two body systems including your:
- Immune system: The immune system protects your body from foreign invaders like bacteria and viruses to prevent infection, illness or diseases. Your immune system is what keeps you healthy.
- Lymphatic system: The lymphatic system is part of your immune system that protects your body from foreign invaders that cause illness, maintains fluid levels throughout your body, absorbs nutrients and fats and removes waste from cells.
As a filter for the fluid that flows through your cells and tissues, lymph nodes clean up and get rid of lymphatic fluid waste and invaders that cause illness, while holding onto the components of your lymphatic fluid that keep you healthy.
Where are lymph nodes located?
Lymph nodes exist throughout your body. They normally reside where two or more major blood vessels come together (converge) on your body including:
- Armpit (axillary).
- Behind your ear.
What do lymph nodes look like?
Lymph nodes look like sprouting kidney beans, where the sprouts are tubes that carry lymphatic fluid around your body (lymphatic channels). Leading into each node are blood vessels. The lymph node has a protective outside layer (capsule), like a shell on the bean that divides parts of the node into rooms with a large open room in the center (cortex). Lymphatic fluid flows through these rooms, which filters the fluid, and it exists in the nodes from the lymphatic channels.
How big are lymph nodes?
Lymph nodes are about the size of a pea, which is less than 1/2 inch. (12 millimeters).
How many lymph nodes are in my body?
There are approximately 600 lymph nodes in your body as an adult. The exact number varies from person to person.
What are lymph nodes made of?
Lymph nodes are made of lymph tissue and different types of cells including:
- White blood cells (lymphocytes).
- B cells.
- T cells.
- Dendritic cells.
- Plasma cells.
Conditions and Disorders
What are common conditions that affect lymph nodes?
Several conditions affect the health of your lymph nodes including:
- Enlarged (swollen) lymph nodes (lymphadenopathy): Lymph nodes swell when your immune system is fighting an infection or an illness (strep throat, mononucleosis, wound infection, HIV).
- Lymphoma: Lymphoma refers to cancers that start in your lymphatic system and include Hodgkin’s lymphoma and non-Hodgkin’s lymphoma.
- Lymphangioleiomyomatosis: A lung disease that causes cells to grow out of control in the lungs, lymph nodes and kidneys.
- Autoimmune lymphoproliferative syndrome: A genetic condition that causes too many white blood cells (lymphocytes) to collect in your lymph nodes, liver and spleen.
- Mesenteric lymphadenitis: A condition that causes swelling (inflammation) of the lymph nodes in your abdomen.
- Kikuchi's disease: A condition that causes lymph nodes to swell and become painful.
- Castleman disease: A group of conditions that cause an overgrowth of cells in your lymphatic system.
What are common signs or symptoms of lymph node conditions?
Symptoms vary for each condition that affects your lymph nodes. The most common symptoms arise with swollen lymph nodes (lymphadenopathy). Symptoms of swollen lymph nodes include:
- Pain or tenderness in your lymph nodes.
- Lymph node increases in size (swelling) that appears as a bulge under your skin.
- Fever, sore throat or a runny nose (signs of respiratory infection).
- Sweating, especially at night.
When lymph nodes swell, that's your body telling you that you’re fighting an illness or infection. If you notice your lymph nodes get bigger and you don’t have symptoms of an illness or infection, visit your healthcare provider for an exam.
What are common tests to check the health of my lymph nodes?
Your provider will check the health and size of your lymph nodes through imaging tests like:
A complete blood count is a blood test that measures how many cells are in a sample of your blood. This can help identify conditions and/or cancers that affect the cells in your lymph nodes.
If you have severe symptoms that affect your lymph nodes, your provider might perform a lymph node biopsy where they remove a small tissue sample of one of your lymph nodes to examine the lymph tissues for abnormalities.
What are common treatments for lymph node conditions?
Your provider will diagnose and offer treatment that is unique to you and your symptoms. Treatment for common lymph node conditions varies but could include:
- Taking antibiotics to clear up any infections.
- Applying a warm compress or taking over-the-counter medicine to treat pain.
- Undergoing chemotherapy, radiation therapy or immunotherapy for certain cancers.
- Taking medicine to treat the condition that caused your lymph nodes to swell.
- Surgery to remove damaged lymph nodes.
How do I keep my lymph nodes healthy?
You can take care of your lymph nodes and your lymphatic system by:
- Staying hydrated and drinking plenty of water.
- Eating a well-balanced diet.
- Exercising regularly.
- Avoiding toxic chemical exposure (pesticides and certain cleaning products).
- Resting and getting enough sleep.
- Using proper wound care to prevent infection after an injury.
A note from Cleveland Clinic
Your lymph nodes are an important part of your body that filters substances to keep you healthy. Taking good care of your body helps your lymph nodes and your lymphatic system work at its best. Talk to your provider if you notice your lymph nodes get bigger or swell, which could be a sign of an illness or an infection.
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