Introduction

Part of the lymphatic system, the lymph nodes are small bean-shaped structures that filter lymphatic fluid and carry infection-fighting white blood cells. The main job of lymph nodes is to aid in the immune system’s role of protecting the body.¹

The lymph nodes indicate the presence of any diseases or infections in your body. Either a minor infection or a more complex health issue, swollen lymph nodes are a cue that your body is actively fighting some kind of threat. It’s important to recognise any potential signs of infection, and understanding their relevance is key to addressing underlying health concerns.

Anatomy and function

Location in the body

There are hundreds of lymph nodes found throughout the body, with the most well-known places in the neck, armpits, and groin. Additionally, you can find lymph nodes along major blood vessels around the abdomen and pelvis regions. These locations are not random; they are carefully selected to optimise their function as early infection responders.² 

Role of lymph nodes in immunity

As a key component of the immune system, the main role of lymph nodes is to filter the lymphatic fluid. This fluid is loaded with lymphocytes, which are infection-fighting white blood cells, and as the lymphatic fluid flows through the nodes, any pathogens are trapped and destroyed.² 

Size and characteristics

Lymph nodes are pea-sized structures. When actively fighting an infection or other abnormal state, however, they are activated and can enlarge up to half an inch. Even though a range of lymph node sizes and characteristics are considered healthy, any changes are clear indicators of potential health issues.³ 

Common causes of swollen lymph nodes

Infection

Fighting infections is an important root of swollen lymph nodes. Distinct microorganisms can determine the characteristics of the swelling:⁴ 

• Bacterial infections: Infections caused by streptococcus or staphylococcus can potentially result in lymph node swelling. These conditions may make the nodes painful and tender, especially near to the infection site. A throat infection is a clear root of swollen lymph nodes 
• Viral infections: The flu, a cold, and mononucleosis, among others, can make your lymph nodes enlarged. Though tender nodes can be observed, they become generally less painful when compared to bacterial infections 
• Fungal infections: Though unusual, fungal infections may also drive lymph node swelling. These usually affect the skin, nails, or respiratory tract, leading to swollen lymph nodes in the affected areas  

Inflammatory state

Rheumatoid arthritis, systemic lupus, and other autoimmune conditions are major drivers of inflammation. Under these conditions, your immune system might mistake healthy tissues as a threat, attacking these areas and leading to chronic inflammation and consequent swelling of lymph nodes.²  

Cancers

Much less common than the other conditions, cancers may also lead to lymph node swelling. Enlarged lymph nodes, in this case, become firm and hard to the yet, although painless.⁵ 

Symptoms and diagnosis

Common symptoms

The distinct roots of lymph node swelling can result in specific sets of symptoms. However, some common signs can be easily identified:⁶ 

Table 1: Common Symptoms of Swollen Lymph Nodes

Physical examination

A healthcare provider will perform a physical examination if you suspect lymph node swelling or experience associated symptoms. The examination assesses node size and location, as well as evaluating any signs of inflammation or infection in the surrounding area.⁶ 

Diagnostic tests

• Blood tests: specific biomarkers can be identified in blood tests. An elevated white blood cell count, for example, is a sign of an active immune response.⁷ 
• Imaging studies: techniques such as ultrasounds, CT scans and MRI scans aid the diagnosis by providing a detailed view of swollen lymph nodes. By determining size and location, along with any potential structural changes in the nodes, an accurate diagnosis can be established.⁷ 
• Biopsy: the removal of a small sample of the affected lymph node and further examination by microscope can confirm a diagnosis when the cause of the swelling remains unclear.⁷ 

Treatment and management

Addressing the underlying issue

• Antibiotics for infections: they can be prescribed when the underlying cause is either a bacterial or fungal infection. It is vital to complete the full course of treatment, even if you already feel better, to ensure that the infection is fully eliminated⁷ 
• Anti-inflammatory medications: this type of treatment can diminish the overactivity of the immune system. By alleviating the symptoms, lymph node swelling is significantly reduced.⁷ 
• Cancer treatment: depending on the type, stage, and location of the cancer, a tailored treatment may include options such as surgery, radiation therapy, chemotherapy, immunotherapy, or a combination of these⁷ 

Self-care measures

Depending on its underlying cause, lymph node swelling should naturally diminish within two weeks. However, self-care measures can boost your healing process. Resting to allow your body to recover, keeping hydrated by drinking lots of fluids, and taking over-the-counter pain relievers might help alleviate symptoms.⁸ 

Monitoring and follow-up

In case you are undergoing treatment, or the cause of your swollen lymph nodes is yet to be determined, monitoring and follow-up is essential. Monitoring changes over time will lead to adjusting your care if needed. Do not hesitate to seek medical attention if your symptoms worsen or persist.  

When should you seek medical attention?

Schedule an appointment with your healthcare provider if you:

• have enlarged nodes in your body for over a month
• have a sore throat and/or swollen node in the neck
• are not sure of the cause of a swollen node
• feel an enlarged node over an inch in size
• have any limits in movement due to a swollen lymph node

Seek urgent healthcare attention in case of: 

• a swollen node in your neck causing trouble breathing or swallowing
• a fever over 40°C
• the skin over the lymph node is red
• enlarged node gets much bigger overnight

Remember not to self-diagnose! Not everyone with swollen lymph nodes requires immediate care. However, visit your healthcare provider if you feel like your nodes are protruding more than usual, are painless, or have lasted longer than you would expect.⁹

Prevention

Adding in easy practices to your routine can significantly reduce the risk of developing lymph node swelling and associated health issues. You should:

• Wash your hands with soap and water or use a hand sanitiser. These regular practices help diminish the risk of getting infected
• Avoid close contact with individuals who have contagious conditions. This is an effective preventative measure, as well as ensuring your vaccinations are up to date 

Summary

Swollen lymph nodes, also known as lymphadenopathy, usually represent an alert that your body might be actively fighting a potential threat – from a mild infection to a more serious or complex health issue. Notable symptoms include lumps, redness, and tenderness at the site of the affected node. Physical examination and diagnostic tests provided by your doctor can help identify the underlying cause of the swelling. 

The sooner the cause is identified and managed, the better the chances of making a full recovery. However, when observing signs like rapid enlargement of nodes, painless swelling, or even breathing difficulty, it is vital to seek immediate medical attention. Beyond prescribed medical treatment, self-care strategies help to alleviate discomfort and support healing. Do not overlook regular medical monitoring and follow-up for assessment of treatment and progress. 

Keywords

1. Lymphadenopathy
2. Lymphatic system
3. Lymph nodes location
4. Immune response
5. Infections
6. Inflammation
7. Bacterial infections
8. Viral infections
9. Fungal infections
10. Autoimmune diseases
11. Cancer diagnosis
12. Lymphatic fluid
13. White blood cells
14. Antibiotics
15. Anti-Inflammatory medications
16. Cancer treatment options
17. Immunizations
18. Autoimmune conditions
19. Diagnostic tests
20. Biopsy procedure
21. Swelling and tenderness
22. Complications of lymph nodes
23. Abscess formation
24. Immunotherapy
25. Preventive measures