Lymph nodes are small, bean-shaped glands throughout the body that play an important role in the immune system. They act as filters for the lymphatic system, helping to remove toxins, waste, and other unwanted substances from the body. Lymph nodes also contain white blood cells called lymphocytes that help fight infection. When bacteria or viruses infect the body, the lymph nodes may swell as they become filled with infection-fighting cells. An enlarged or swollen lymph node is often a sign that the body is fighting an infection. In most cases, swollen lymph nodes will return to normal size once the infection is gone. However, sometimes a lymph node infection can persist and cause complications if left untreated.
What causes infected lymph nodes?
There are several potential causes of infected lymph nodes:
- Bacterial infections – Bacteria like staphylococcus or streptococcus can enter the lymph nodes through cuts or open wounds and cause an infection.
- Viral infections – Viruses like mononucleosis, chickenpox, or shingles can spread to lymph nodes and cause swelling and inflammation.
- Skin infections – Skin infections like cellulitis or abscesses near lymph nodes can spread into the lymph nodes.
- Other infections – Fungal infections, parasites, and tuberculosis can also infect lymph nodes when the germs enter the body.
- Cancer – Lymphoma and leukemias cause lymph node swelling due to abnormal growth of lymphocytes.
In most cases of infected lymph nodes, the body’s immune system can fight off the infection without medical treatment. However, some infections persist and require antibiotics or drainage to get rid of the infection.
Signs and symptoms of infected lymph nodes
Inflamed or infected lymph nodes often cause distinct signs and symptoms:
- Swelling or enlargement of lymph nodes
- Tenderness or pain in the lymph node area
- Redness and warmth over the skin of the swollen node
- Fever due to a spreading infection
- Chills, fatigue, and body aches from the infection
- Pus draining from the node if an abscess forms
Swollen nodes are most commonly located in the neck, underarm, or groin region, depending on the location of the infection. For example, a sore throat can trigger swollen neck lymph nodes while an infection on the leg may cause groin lymph node swelling.
Complications from untreated infected lymph nodes
In most healthy people, swollen lymph nodes will heal once the infection clears. However, leaving an inflamed or infected lymph node untreated can sometimes lead to complications:
- Abscess formation – Bacteria and pus can get trapped in the lymph node, forming an abscess or pocket of infection. Abscesses cause pain, swelling, and redness over the skin and may rupture and drain pus if not treated.
- Spread of infection – Untreated infections may continue to spread from the lymph node to other parts of the body through the lymphatic system. This can lead to lymphangitis, septicemia, or other systemic infections.
- Lymphadenitis – Chronic, recurrent infection of lymph nodes is called lymphadenitis. This can lead to scarring and impaired function of the lymph nodes.
- Lymphedema – Damaged, blocked, or removed lymph nodes can cause lymphatic fluid drainage issues leading to swelling (lymphedema) of the arms, legs, head, or other areas.
- Cancer risk – Chronic infections increase the risk of cancer developing in the affected lymph nodes later.
Seeking prompt medical treatment is crucial if any signs of infection in lymph nodes persist for more than 1-2 weeks.
When to see a doctor
It’s important to see a doctor for evaluation of swollen or tender lymph nodes if you:
- Have lymph node swelling that persists longer than 2 weeks
- Have an abscess or pus draining from a lymph node
- Have red streaking from the node area suggesting lymphangitis
- Have swelling in multiple lymph node areas like the neck, underarms, and groin
- Have lymph node swelling combined with fever, chills, and fatigue
- Have risk factors for infections like HIV or immune system problems
Prompt medical evaluation and treatment helps prevent complications of a lymph node infection. Your doctor can drain abscesses, obtain cultures to identify the type of infection, and prescribe antibiotics when needed for bacterial infections. Hospital care may be required for severe lymph node infections.
Diagnosing infected lymph nodes
To diagnose an infected lymph node, doctors will typically:
- Perform a physical exam to feel for swollen or tender lymph nodes
- Ask about any recent infections that could cause lymphadenitis
- Look for signs of skin infection, open wounds, or abscesses near the swollen nodes
- Order blood tests to look for elevated white blood cell counts or markers of infection
- Use imaging tests like CT scan, MRI, or ultrasound to evaluate lymph nodes
- Drain and culture any abscesses to identify the type of infection
- Perform a lymph node biopsy if cancer is suspected as the cause
Identifying the source of the infection guides treatment options. Your doctor will also check for any complications like lymphangitis or spreading infections.
Treating infected lymph nodes
Treatment depends on the cause and severity of the lymph node infection:
- Mild infections – Swollen nodes from minor viral or bacterial illnesses may be managed with rest, fluids, warm compresses, and over-the-counter pain medicine. The nodes typically improve on their own as the infection resolves.
- Antibiotics – Bacterial infections are treated with a course of oral antibiotics or intravenous antibiotics if the infection is severe. The antibiotics help clear the bacteria from the lymph node and prevent complications.
- Abscess drainage – Collections of pus in lymph nodes need to be drained surgically or with a needle aspiration. Antibiotics are also prescribed.
- Hospital care – Severe infections causing lymphangitis, high fevers, sepsis, or multiple swollen nodes often require hospitalization for IV antibiotics and drainage procedures.
- Surgery – Lymph nodes or affected tissues may need excision if there is extensive scarring or a high risk of cancer developing.
Most people recover fully when infections are treated quickly. Good hygiene and wound care help prevent infected lymph nodes from recurring. Seek prompt medical care if lymph nodes remain swollen for over 2 weeks.
Potential complications
Even with treatment, infected lymph nodes can sometimes lead to complications:
- Chronic or recurrent infections causing lymphadenitis
- Abscesses may recur if not fully drained
- Spread of infection to the bloodstream (sepsis) or vital organs
- Permanent scarring and damage to lymph drainage pathways
- Increased risk of later cancer in damaged nodes
Severe infections require strong antibiotics or weeks of treatment. Follow up closely with your doctor to monitor for complications or worsening swelling. Report any persisting fever, chills, fatigue, or redness spreading from lymph nodes.
Recovery and outlook
With appropriate medical treatment, most simple lymph node infections resolve within 1-2 weeks. The nodes will decrease in size and tenderness as the body clears the infection.
It may take 4-6 weeks for more severe infections to fully resolve. Draining abscesses or surgical removal also lengthens recovery time. Some enlarged nodes may persist for months after infections as they heal.
Overall, the outlook is very good when infected lymph nodes are treated promptly. Most healthy adults make a full recovery with no lasting complications. Recurring infections or chronic lymphadenitis have a less favorable outlook, especially in those with weakened immune systems. Slow-growing lymph node infections related to tuberculosis or cancer may be more difficult to treat as well.
Close follow-up care is important, even after infections improve. Report any signs of new swelling, abscesses, or redness to your doctor right away. With appropriate treatment, infected lymph nodes generally do not cause any permanent damage or disability.
Prevention
You can take steps to help prevent infected lymph nodes:
- Practice good hygiene – wash hands regularly, shower daily, and keep cuts/scrapes clean.
- Treat skin infections early to prevent spread to lymph nodes.
- Get appropriate treatment for any infections like strep throat that could trigger lymphadenitis.
- Avoid exposing lymph nodes to bacteria during manicures, shaving, or tattoos.
- Manage chronic conditions like HIV, diabetes, and skin conditions.
- Quit smoking and avoid secondhand smoke.
Staying healthy and avoiding infections can help keep lymph nodes infection-free. See your doctor about swollen nodes that last more than a couple weeks or keep recurring. Prompt treatment helps prevent potential complications down the road.
When to see a doctor
Consult your doctor if you experience any of the following:
- Lymph node swelling lasting longer than 2 weeks
- Pus or abscess formation in lymph nodes
- Red streaks extending from swollen nodes
- Persistent fever, chills, and body aches
- Swelling in multiple lymph node regions
- Signs the infection is worsening or spreading
Getting prompt medical attention helps prevent complications of an infected lymph node. Your doctor can provide a diagnosis, prescribe antibiotics if needed, drain any abscesses, and monitor you for improvement. Call right away if an enlarged lymph node is not getting better with home treatment.
Conclusion
Infected lymph nodes are usually a sign the body is fighting an illness. While mild infections often resolve on their own, it’s important not to ignore swollen or painful lymph nodes. Seeking medical treatment is crucial if lymphadenitis persists longer than 1-2 weeks or shows signs of abscess formation or spreading infection.
With a quick diagnosis and appropriate antibiotics or drainage, most infected lymph nodes improve without complication. Good hygiene and wound care help prevent recurrence. Closely monitor lymph nodes after infections for any new swelling or redness. Prompt treatment helps avoid potentially serious complications and improves the outlook for complete recovery.