Lymph nodes are small, bean-shaped glands that are part of the lymphatic system. They play an important role in the body’s immune response by filtering lymph fluid and trapping viruses, bacteria, and other causes of illness. Lymph nodes can become swollen and tender when fighting an infection. In most cases, swollen lymph nodes will return to normal size once the infection is gone. But can swollen lymph nodes heal on their own or do they require medical treatment? Here is a look at how lymph nodes work, what causes them to swell, and whether they can heal naturally.
What are lymph nodes and what do they do?
Lymph nodes are small structures that work as part of the lymphatic system to protect the body against infection and disease. The lymphatic system is a network of vessels, ducts, and nodes that carries lymph fluid throughout the body. Lymph is a clear fluid that contains white blood cells, especially lymphocytes, that help fight infection. There are hundreds of lymph nodes located throughout the body, but they are concentrated in areas such as the neck, armpits, chest, abdomen, and groin.
The lymph nodes filter lymph fluid as it travels through the lymphatic system. Inside each node are immune cells like lymphocytes and macrophages that can detect and destroy viruses, bacteria, and other invading microbes. The nodes act as checkpoints along the lymphatic system to trap foreign substances and prevent them from infecting the rest of the body. Normal lymph nodes are tiny – less than half an inch in size – and feel soft and smooth.
What causes lymph nodes to swell?
When your body is fighting an infection, lymph nodes may become swollen as they fill with lymphocytes and other immune cells working hard to destroy the infection. Swollen lymph nodes are also called enlarged or inflamed lymph nodes. The medical term for swollen lymph nodes is lymphadenopathy.
Enlarged lymph nodes often feel like tender, painful lumps under the skin. They may be the size of a pea or as large as a grape. The most common causes of swollen lymph nodes are:
- Viral infections – like the common cold, flu, mono, chickenpox
- Bacterial infections – such as strep throat, pneumonia, skin infections
- Other infections – including fungal infections, tuberculosis, sexually transmitted infections
- Inflammation and immune disorders – rheumatoid arthritis, lupus, HIV/AIDS
- Cancer – leukemia, lymphoma
In children, the most common cause of enlarged lymph nodes is upper respiratory infections or other viral illnesses. In adults, swollen lymph nodes are most often caused by the common cold, flu, skin infections, or sexually transmitted diseases like gonorrhea or chlamydia. If the swelling persists for more than 2-4 weeks, it may indicate a more serious infection or a problem with the immune system. Swollen lymph nodes from cancer is rare, but always a possibility.
Where do swollen lymph nodes appear?
The location of swollen lymph nodes can provide clues as to the underlying cause of the swelling. Lymph nodes in different areas of the body drain fluid from different regions. For example:
- Swollen lymph nodes in the neck may be from infections of the mouth, throat, ears, or scalp. The neck has the highest concentration of lymph nodes in the body.
- Swollen nodes under the arm could indicate an infection of the chest, breast, shoulder, or upper arm.
- Groin lymph nodes may swell due to infections of the genitals, lower abdomen, pelvis, buttocks, or lower body.
- Abdominal lymph nodes can become enlarged from gastrointestinal infections or inflammation.
If multiple lymph nodes in different regions of the body are swollen, it may point to a widespread infection or an immune disorder.
Can swollen lymph nodes heal on their own?
In most cases, enlarged lymph nodes will return to normal size once the infection clears. The nodes shrink back down as the trapped viruses, bacteria, and other microbes are destroyed by the immune cells inside the node. This is especially true for temporary viral illnesses like the common cold or flu. As your immune system fights off the virus, the swollen lymph nodes should recede within 2-4 weeks.
However, lymph nodes may not always heal naturally. Treatment may be needed if:
- The swelling persists longer than 4 weeks
- The node continues to enlarge
- The node feels very hard or becomes immobile
- You develop a fever, night sweats, unexpected weight loss
- The node is red, warm, and tender (signs of infection)
Prolonged, enlarged lymph nodes can signify:
- An untreated infection like tuberculosis
- An autoimmune disorder disrupting lymph drainage
- Cancer spreading to the lymph nodes
Leukemia and lymphoma specifically affect the lymph nodes and other lymphatic tissue. Seek prompt medical attention if your swollen lymph nodes do not recede after a temporary illness, in order to determine if further testing or treatment is required.
How are swollen lymph nodes evaluated?
If enlarged lymph nodes do not resolve on their own, a doctor can evaluate them and determine an underlying cause through:
- Medical history – Discussion of symptoms, recent illnesses, chronic conditions, family history, medications, travel, potential exposures
- Physical exam – Looking for signs of infection, feeling the size, texture, warmth and tenderness of nodes
- Imaging tests – Ultrasound, CT scan, MRI to examine lymph nodes internally
- Biopsy – Removing a small sample of the lymph node for testing
- Blood tests – Complete blood count, cultures to uncover infection or inflammation
Based on the results of the evaluation, appropriate treatment can be provided if needed. Antibiotics are prescribed for bacterial infections while antiviral medication may help chronic viral illnesses. Cancer treatment would be recommended if leukemia or lymphoma cells are found in a lymph node biopsy. Surgery is sometimes required to drain an abscessed lymph node.
What helps reduce swollen lymph nodes?
While waiting for enlarged lymph nodes to heal, the following self-care tips may help reduce discomfort and swelling:
- Apply warm compresses to the affected lymph nodes
- Take over-the-counter pain relievers like acetaminophen or ibuprofen
- Gently massage the lymph nodes to encourage drainage
- Avoid tight clothing over swollen nodes
- Get plenty of rest to allow your immune system to work
- Stay well hydrated and eat a balanced diet
Antibiotics will be prescribed if a bacterial infection is the cause. Avoid any harsh soaps, creams, or ointments on swollen nodes which could further irritate them. See your doctor promptly if symptoms worsen or persist longer than expected.
Can lymph nodes be removed?
Surgical removal of lymph nodes is called a lymph node dissection or lymphadenectomy. This is only done when absolutely necessary, such as:
- To diagnose an unknown cause of swollen lymph nodes by removing some nodes for biopsy
- To stop the spread of cancer cells in lymph nodes
- To remove severely enlarged or painful nodes that won’t recede with other treatments
Lymph nodes play an important role in the immune system, so they should not be removed unless there is a compelling reason to do so. Even when lymph nodes are surgically removed, the lymphatic system usually continues to function normally.
Are there complications from swollen lymph nodes?
While swollen lymph nodes most often resolve without issue, potential complications can arise in some cases:
- Infection risk – Chronically enlarged lymph nodes may contain lingering bacteria that could spread. Abscessed nodes may need antibiotics or drainage.
- Pain and swelling – Large, inflamed nodes can be uncomfortable. Swelling in the neck/throat could affect swallowing or breathing.
- Lymphedema – Buildup of lymph fluid can cause swelling in an arm or leg if drainage through nodes is disrupted.
- Cancer spread – Untreated lymphoma/leukemia cells may metastasize from lymph nodes to other organs.
Seek prompt medical treatment if swollen lymph nodes are accompanied by fever, increasing pain, difficulty swallowing/breathing, or other concerning symptoms. Catching and addressing the underlying problem early can help prevent complications.
Can lymph nodes heal after cancer treatment?
Lymph nodes affected by cancer often remain permanently enlarged, even after treatment. The lymphatic system plays a key role in certain cancers spreading to lymph nodes, including:
- Breast cancer spreading to nodes under the arms
- Melanoma spreading to lymph nodes near the tumor site
- Head and neck cancers spreading to neck lymph nodes
- Gynecologic cancers spreading to pelvic and groin nodes
When cancer is treated with surgery, radiation, chemotherapy, or immunotherapy, the malignant cells in the lymph nodes can be eliminated. However, the inflammation and structural changes within the nodes often persist. Scar tissue and fibrosis replace the cancer cells. For this reason, lymph nodes enlarged by metastatic cancer do not typically shrink back to normal size after treatment. But the nodes are no longer cancerous.
It’s also common for some lymph nodes to be removed during cancer surgery. For example, a lumpectomy for breast cancer includes removing one or more lymph nodes to check for cancer spread. Loss of several lymph nodes does not impair the overall function of the lymphatic system.
Can you prevent lymph nodes from swelling?
There is no guaranteed way to prevent lymph node swelling, since the nodes naturally enlarge as they work to filter out infections. Steps you can take to stay healthy and avoid illnesses that could trigger swollen lymph nodes include:
- Washing hands frequently and cleaning wounds to avoid infections
- Eating a balanced diet to support the immune system
- Exercising regularly to boost lymph circulation
- Avoiding toxins like smoking that could damage lymph nodes
- Using protection during sex to prevent sexually transmitted diseases
- Staying up-to-date on vaccinations to prevent infections
Pay attention to any swollen nodes that develop, especially those that last more than a few weeks. Seek medical advice to diagnose and treat any underlying illness before complications arise.
Conclusion
In most instances, swollen lymph nodes will return to normal size once an infection is cleared by the immune system. The lymph nodes naturally reduce in size as the trapped microbes are destroyed and the inflammation subsides. However, lymph nodes that remain chronically enlarged or keep growing could indicate a serious infection, immune disorder, or cancer that requires medical treatment.
It’s important to monitor swollen lymph nodes and watch for signs they are not resolving on their own, such as nodes that feel very hard or immobile. Proper evaluation and testing can determine if antibiotic medication, antiviral treatment, surgery, or other interventions are needed. Lymph nodes affected by cancer may not heal fully, but cancer cells can be eliminated even if some swelling persists.
While swollen lymph nodes often resolve through the body’s own healing mechanisms, it’s wise to seek medical advice if nodes stay enlarged longer than expected. Catching and addressing the root cause early provides the best outcome.