Lymph Nodes: Swollen Glands Causes, Symptoms & Treatment

What Are Lymph Nodes and What Do They Do?

Lymph nodes are small, bean-shaped organs that are part of the lymphatic system. They filter lymph fluid, trap pathogens like bacteria and viruses, and produce immune cells to fight infections. The human body contains approximately 600-700 lymph nodes distributed throughout the body.

Lymph nodes are essential components of your immune system, acting as biological filters and immune response centers. These small structures, typically measuring between 0.1 and 2.5 centimeters in diameter, are strategically positioned throughout your body to intercept and neutralize potential threats before they can spread and cause systemic illness. Understanding how lymph nodes function helps explain why they become swollen during infections and other medical conditions.

The lymphatic system works parallel to your blood circulatory system, but instead of carrying blood, it transports a clear fluid called lymph. This fluid originates from blood plasma that has leaked out of capillaries into the surrounding tissues. As lymph travels through lymphatic vessels, it passes through multiple lymph nodes where it is filtered and examined by specialized immune cells. Think of lymph nodes as security checkpoints that monitor everything passing through your body's tissues.

Inside each lymph node, there are different zones containing various types of immune cells. The outer cortex contains B lymphocytes organized into follicles, which are responsible for producing antibodies. The inner region, called the paracortex, houses T lymphocytes that directly attack infected cells and coordinate immune responses. When the lymph node encounters a pathogen, these cells rapidly multiply, causing the characteristic swelling we associate with an active immune response.

Lymph nodes also play a crucial role in immune memory. When they successfully fight off an infection, some of the immune cells become memory cells that remain in the lymph nodes for years or even decades. This explains why you may not get certain infections twice – your lymph nodes have already learned how to recognize and quickly neutralize those specific pathogens. This same mechanism is the basis for how vaccines work, training your lymph nodes to recognize threats before you encounter them naturally.

Main Functions of Lymph Nodes

• Filtration: Remove bacteria, viruses, cancer cells, and other foreign particles from lymph fluid
• Immune cell production: Produce and store B and T lymphocytes that fight infection
• Antibody production: Generate antibodies specific to pathogens encountered
• Immune surveillance: Constantly monitor for abnormal or foreign cells
• Antigen presentation: Display pathogen fragments to activate other immune cells

How the Lymphatic System Works

The lymphatic system consists of an extensive network of vessels, nodes, and organs working together to maintain fluid balance and immune function. Lymph fluid is collected from tissues throughout the body and directed through progressively larger lymphatic vessels toward two main ducts that empty into large veins near the heart. Along this pathway, the fluid passes through numerous lymph nodes that screen it for potential threats.

Unlike the blood circulatory system, the lymphatic system does not have a central pump like the heart. Instead, lymph movement depends on muscle contractions during normal movement, breathing, and specialized one-way valves in lymphatic vessels that prevent backflow. This is why regular physical activity is important for lymphatic health – sedentary lifestyles can lead to sluggish lymph flow and potential fluid accumulation in tissues, a condition known as lymphedema.

Where Are Lymph Nodes Located in the Body?

Lymph nodes are found throughout the body, with the most easily felt locations being the neck (cervical), under the jaw (submandibular), armpits (axillary), and groin (inguinal). Internal lymph nodes in the chest, abdomen, and pelvis can only be seen with imaging studies.

Understanding lymph node locations helps you identify which areas of your body might be affected when you notice swelling. Lymph nodes are strategically positioned in clusters at key points throughout the body, particularly where lymphatic vessels from different body regions converge. Each group of lymph nodes drains a specific anatomical region, which is why healthcare providers can often identify the source of an infection based on which lymph nodes are swollen.

The lymph nodes you can most easily feel are called superficial lymph nodes. These are located just beneath the skin and become palpable when they enlarge. During a routine physical examination, doctors systematically check these accessible locations to assess your lymphatic health. However, it's important to understand that having palpable lymph nodes does not necessarily indicate a problem – many healthy people have small, soft lymph nodes that can be felt, especially in the neck and groin regions.

Internal Lymph Node Groups

Many lymph nodes are located deep within the body and cannot be felt during a physical examination. These internal nodes drain organs and deep tissues. The mediastinal lymph nodes in the chest drain the lungs, heart, and esophagus. Mesenteric lymph nodes in the abdomen drain the intestines. These internal nodes can only be evaluated through imaging studies such as CT scans, MRI, or PET scans when there is clinical concern.

What Causes Swollen Lymph Nodes?

The most common cause of swollen lymph nodes is infection, particularly viral infections like the common cold, flu, or mononucleosis. Bacterial infections, autoimmune diseases, certain medications, and rarely cancer (lymphoma or metastatic disease) can also cause lymph node enlargement.

Swollen lymph nodes, medically termed lymphadenopathy, occur when lymph nodes enlarge in response to various stimuli. The swelling happens because the lymph node is actively responding to a challenge – whether that's an infection, inflammation, or abnormal cell growth. Understanding the various causes helps distinguish between benign, self-limiting conditions and those requiring medical attention.

The mechanism behind lymph node swelling differs depending on the underlying cause. In infections, immune cells within the lymph node rapidly multiply to fight the invading pathogen, causing the node to expand. In inflammatory conditions, the node responds to signals from damaged tissues. In cancer, either the lymph node's own cells become malignant (as in lymphoma) or cancer cells from elsewhere in the body travel through lymphatic vessels and take up residence in the node (metastasis).

It's reassuring to know that the vast majority of swollen lymph nodes are caused by benign conditions, particularly common infections. Studies show that approximately 75% of localized lymphadenopathy cases are due to infections, with viral infections being the most frequent culprit. However, the likelihood of a serious underlying cause increases with age and certain clinical features, which is why persistent or concerning lymph node enlargement warrants medical evaluation.

Infectious Causes

Infections are by far the most common cause of swollen lymph nodes. When your body detects an invading pathogen, the nearest lymph nodes spring into action, producing immune cells and antibodies to fight the infection. This immune response causes the nodes to swell, often becoming tender to the touch. The swelling typically resolves as the infection clears.

• Viral infections: Common cold, influenza, infectious mononucleosis (Epstein-Barr virus), HIV, measles, rubella, chickenpox
• Bacterial infections: Strep throat, skin infections (cellulitis), cat scratch disease, tuberculosis, sexually transmitted infections
• Parasitic infections: Toxoplasmosis, leishmaniasis
• Fungal infections: Histoplasmosis, coccidioidomycosis (in endemic regions)

Non-Infectious Causes

While infections dominate as the cause of swollen lymph nodes, several non-infectious conditions can also lead to lymphadenopathy. Autoimmune diseases cause the immune system to attack the body's own tissues, which can result in chronic lymph node enlargement. Certain medications can trigger reactions that include swollen lymph nodes. Malignancies, though less common, represent an important category that requires careful evaluation.

• Autoimmune diseases: Systemic lupus erythematosus (SLE), rheumatoid arthritis, Sjögren's syndrome, sarcoidosis
• Medications: Phenytoin (seizure medication), some antibiotics, allopurinol (gout medication)
• Lymphoma: Hodgkin lymphoma, Non-Hodgkin lymphoma (cancer originating in lymph nodes)
• Metastatic cancer: Cancer cells spreading from primary tumors elsewhere in the body
• Leukemia: Blood cancers that can affect lymph nodes

What Symptoms Accompany Swollen Lymph Nodes?

Swollen lymph nodes may cause a visible or palpable lump, tenderness or pain, warm skin over the area, and associated symptoms like fever, fatigue, or night sweats depending on the underlying cause. The characteristics of the swollen nodes and accompanying symptoms help determine the cause.

The symptoms associated with swollen lymph nodes vary considerably depending on the underlying cause. In many cases, the lymph node swelling itself is the most noticeable symptom, but accompanying signs can provide valuable clues about what's causing the enlargement. Healthcare providers evaluate both the characteristics of the lymph nodes themselves and any systemic symptoms to narrow down the diagnosis.

When examining lymph nodes, several features are assessed: size, consistency (soft versus hard), mobility (whether the node moves freely or is fixed to surrounding tissue), tenderness, and the number and distribution of affected nodes. Each of these characteristics provides information about the likely cause. For example, nodes that are soft, tender, and mobile are typically reactive to infection, while hard, fixed, and painless nodes raise more concern for malignancy.

Local Symptoms

• Palpable lump or swelling: You may notice a bump under the skin, particularly in the neck, armpit, or groin
• Tenderness or pain: Infected lymph nodes are often tender when touched or may ache spontaneously
• Warm, red skin: The skin over an infected lymph node may feel warm and appear reddish
• Restricted movement: Swollen cervical nodes may cause discomfort when turning the head

Systemic Symptoms (Constitutional Symptoms)

Many conditions that cause lymph node swelling also produce body-wide symptoms. These systemic symptoms, sometimes called "B symptoms" in the context of lymphoma, can indicate a more significant underlying condition and warrant medical attention:

• Fever: Elevated temperature often accompanies infections causing lymphadenopathy
• Night sweats: Drenching sweats that soak clothing or bedding, especially concerning for lymphoma or tuberculosis
• Unexplained weight loss: Losing more than 10% of body weight over 6 months without trying
• Fatigue: Persistent tiredness that doesn't improve with rest
• Sore throat: Common with upper respiratory infections causing cervical lymphadenopathy
• Skin rash: May accompany viral infections or autoimmune conditions

When Should You See a Doctor for Swollen Lymph Nodes?

See a doctor if swollen lymph nodes persist more than 2-4 weeks, are larger than 2 cm, hard and immobile, occur without obvious infection, affect multiple body regions, or are accompanied by unexplained weight loss, night sweats, or persistent fever.

Most swollen lymph nodes are a normal response to infection and resolve on their own as the infection clears. However, certain characteristics warrant medical evaluation to rule out more serious underlying conditions. Understanding when to seek care helps ensure that concerning cases are appropriately investigated while avoiding unnecessary worry about common, benign lymph node swelling.

Healthcare providers use a combination of history, physical examination, and sometimes laboratory tests or imaging to evaluate lymphadenopathy. The approach depends on the clinical picture – a young adult with tender, mobile neck nodes during cold season likely needs only observation, while an older adult with hard, painless nodes and systemic symptoms requires more comprehensive evaluation.

Age is an important factor in the evaluation of lymphadenopathy. In children and young adults, the majority of lymph node enlargement is benign and often related to their more robust immune responses to common infections. However, the probability of serious underlying pathology increases with age, and lymphadenopathy in adults over 40 generally warrants closer attention. This doesn't mean that swollen lymph nodes in older adults are necessarily concerning – but they may require more thorough evaluation.

Seek Medical Attention If You Notice:

• Lymph nodes that continue to grow or don't shrink after 2-4 weeks
• Nodes that are hard, rubbery, or feel fixed in place
• Painless swelling that gradually increases in size
• Swelling in multiple areas of the body at once
• Unexplained fever lasting more than 2 weeks
• Drenching night sweats
• Unintentional weight loss (more than 5% of body weight)
• Persistent fatigue that doesn't improve with rest
• Easy bruising or unusual bleeding
• Difficulty breathing, swallowing, or opening mouth fully

How Are Swollen Lymph Nodes Diagnosed and Evaluated?

Diagnosis begins with a detailed history and physical examination. Additional tests may include blood work (complete blood count, inflammatory markers), serological tests for specific infections, imaging (ultrasound, CT scan), and in some cases fine needle aspiration or excisional biopsy of the lymph node.

The diagnostic approach to lymphadenopathy is guided by clinical findings and the likelihood of various underlying causes. Most cases can be adequately assessed through history and physical examination alone, with additional testing reserved for cases where there is clinical concern or the diagnosis remains unclear. The goal is to identify cases requiring intervention while avoiding unnecessary invasive testing for benign, self-limiting conditions.

A thorough history helps identify potential exposures and risk factors. The clinician will ask about recent infections, animal contacts, travel to areas endemic for certain diseases, sexual history, medication use, and any family history of cancer or autoimmune disease. The duration and progression of the lymph node swelling, associated symptoms, and any recent similar episodes are all relevant information.

Physical examination assesses the characteristics of the enlarged lymph nodes and searches for additional findings. The examiner notes the size, location, number, consistency, mobility, and tenderness of affected nodes. A complete examination also evaluates other lymph node regions, checks for an enlarged spleen or liver, examines the skin for rashes or suspicious lesions, and assesses the ears, nose, and throat for sources of infection.

Laboratory Tests

• Complete blood count (CBC): May reveal infections (elevated white blood cells), anemia, or abnormal cell populations suggesting leukemia or lymphoma
• Inflammatory markers: ESR and CRP may be elevated in infections or inflammatory conditions
• Serological tests: Testing for specific infections such as EBV (mononucleosis), CMV, HIV, toxoplasmosis, or cat scratch disease
• Metabolic panel: Liver and kidney function tests, LDH (elevated in some lymphomas)
• Autoimmune markers: ANA, rheumatoid factor if autoimmune disease is suspected

Imaging Studies

• Ultrasound: Often the first imaging study, useful for evaluating superficial lymph nodes, distinguishing benign from suspicious features
• CT scan: Provides detailed images of internal lymph nodes in chest, abdomen, and pelvis; helpful for staging if malignancy is suspected
• MRI: Particularly useful for head and neck lymph nodes
• PET scan: May be used to evaluate metabolic activity of lymph nodes when lymphoma is suspected

Tissue Sampling

When imaging and blood tests don't provide a definitive diagnosis, or when there is high suspicion for malignancy, tissue sampling may be necessary:

• Fine needle aspiration (FNA): A thin needle extracts cells from the lymph node for examination; minimally invasive but may not provide enough tissue for complete diagnosis
• Core needle biopsy: Uses a larger needle to obtain a tissue sample; provides more material than FNA
• Excisional biopsy: Surgical removal of the entire lymph node; provides the most tissue and is preferred when lymphoma is suspected

How Are Swollen Lymph Nodes Treated?

Treatment depends entirely on the underlying cause. Infectious causes may require antibiotics, antivirals, or antifungals. Many viral infections require only supportive care while the body fights the infection. Serious conditions like lymphoma require specialized oncologic treatment. Most swollen lymph nodes resolve spontaneously within 2-4 weeks.

There is no single treatment for swollen lymph nodes because the swelling itself is a symptom rather than a disease. The appropriate treatment depends entirely on identifying and addressing the underlying cause. For the majority of cases caused by common infections, the lymph nodes will return to normal size once the infection resolves, often without any specific treatment beyond supportive care.

The approach to treatment begins with accurate diagnosis. Once the cause is identified, targeted therapy can be initiated. For many patients, the diagnostic evaluation reveals a benign cause, and reassurance combined with watchful waiting is the most appropriate management. Understanding that lymph node swelling is usually a sign of the immune system working normally can help alleviate anxiety during the recovery period.

Treatment Based on Cause

Viral Infections: Most viral infections causing lymphadenopathy are self-limiting and don't require specific antiviral treatment. Supportive care includes rest, adequate hydration, and over-the-counter medications for symptom relief (fever reducers, pain relievers). Infectious mononucleosis, caused by Epstein-Barr virus, may cause prolonged lymph node swelling and fatigue, but eventually resolves on its own.

Bacterial Infections: When bacteria are the identified cause, antibiotics are typically prescribed. The specific antibiotic depends on the suspected or confirmed bacterial species. For skin infections causing nearby lymph node swelling, oral antibiotics often suffice. Dental infections may require both antibiotics and dental treatment. Certain infections like tuberculosis require prolonged, specialized antibiotic regimens.

Autoimmune Diseases: Lymphadenopathy associated with autoimmune conditions generally improves when the underlying disease is controlled. Treatment may include corticosteroids, disease-modifying antirheumatic drugs (DMARDs), or biologic agents depending on the specific condition.

Cancer: When lymphoma or metastatic cancer is diagnosed, treatment is directed by oncology specialists and may include chemotherapy, radiation therapy, immunotherapy, targeted therapy, or stem cell transplantation depending on the specific type and stage of cancer.

Self-Care Measures for Benign Lymphadenopathy

• Rest: Allow your body to focus energy on fighting infection
• Warm compresses: May provide comfort for tender lymph nodes
• Over-the-counter pain relievers: Acetaminophen or ibuprofen can reduce pain and fever
• Adequate hydration: Helps support immune function
• Avoid squeezing or manipulating: Don't repeatedly press or massage swollen lymph nodes

What Is Lymphedema and How Is It Related to Lymph Nodes?

Lymphedema is swelling caused by lymph fluid accumulation when the lymphatic system is damaged or blocked. It most commonly affects the arms or legs and can result from lymph node removal during cancer surgery, radiation therapy, or less commonly from inherited conditions. While not curable, lymphedema can be managed with compression therapy, specialized massage, and exercise.

Lymphedema represents a distinct condition from swollen lymph nodes, though both involve the lymphatic system. While swollen lymph nodes occur when the nodes themselves enlarge, lymphedema happens when lymph fluid cannot drain properly and accumulates in tissues, causing swelling in the affected body region. This occurs when lymphatic vessels or lymph nodes are damaged, removed, or blocked.

The most common cause of lymphedema in developed countries is cancer treatment, particularly surgery and radiation therapy. When lymph nodes are removed during breast cancer surgery (axillary lymph node dissection) or when radiation damages lymphatic vessels, the normal drainage pathway for lymph fluid is disrupted. This can lead to gradual swelling of the arm on the affected side. Similarly, treatment for melanoma, gynecological cancers, or prostate cancer can cause leg lymphedema when pelvic or groin lymph nodes are removed or irradiated.

Globally, the most common cause of lymphedema is a parasitic infection called filariasis, which affects over 100 million people primarily in tropical regions. The parasite larvae, transmitted by mosquito bites, mature in the lymphatic system and cause obstruction, leading to severe swelling often called elephantiasis. This condition is rare in North America, Europe, and other developed regions but represents a major public health concern in endemic areas.

Symptoms of Lymphedema

• Swelling in the arm, leg, or other body part, often starting gradually
• Feeling of heaviness or tightness in the affected limb
• Restricted range of motion
• Recurring skin infections (cellulitis) in the affected area
• Skin changes including thickening or hardening over time

Management of Lymphedema

While lymphedema cannot typically be cured, proper management can significantly reduce swelling, prevent complications, and improve quality of life. Treatment is often provided by certified lymphedema therapists and may include:

• Complete decongestive therapy (CDT): The gold standard treatment combining manual lymphatic drainage, compression bandaging, skin care, and exercise
• Compression garments: Custom-fitted sleeves or stockings worn daily to maintain reduction achieved with CDT
• Manual lymphatic drainage (MLD): Specialized gentle massage technique that encourages lymph flow
• Exercise: Specific exercises can help pump lymph fluid through the system
• Skin care: Meticulous skin hygiene prevents infections that can worsen lymphedema
• Pneumatic compression: Mechanical pumps that apply sequential pressure

How Can You Check Your Own Lymph Nodes?

You can perform a self-examination of superficial lymph nodes in your neck, under your jaw, behind your ears, armpits, and groin. Use your fingertips to gently feel for any lumps or swelling, compare both sides of your body, and note the size, tenderness, and consistency of any nodes you feel.

Self-examination of lymph nodes can help you become familiar with your body's normal state and recognize when something changes. Many healthy people can feel small, soft lymph nodes in certain locations, particularly in the groin and sometimes in the neck. By knowing your baseline, you'll be better able to identify new swelling or changes that might warrant medical attention.

It's important to approach self-examination with the right perspective. The goal is not to diagnose yourself but to monitor for changes and know when to seek professional evaluation. Finding a palpable lymph node does not mean something is wrong – as mentioned, many healthy people have small, soft nodes that can be felt. The concerning features are significant size increase, new nodes, hard consistency, or nodes that don't shrink over time.

Step-by-Step Self-Examination

Neck (Cervical Nodes): Tilt your head slightly to one side to relax the neck muscles. Using the pads of your fingertips (not the tips), gently press in a circular motion along the side of your neck from behind the ear down to the collarbone. Feel along the front of the neck near the windpipe. Repeat on the other side and compare.

Under the Jaw (Submandibular Nodes): Tilt your head slightly back and use your fingertips to feel along the underside of the jawbone on both sides. These nodes drain the mouth and lower face.

Behind the Ears (Posterior Auricular Nodes): Feel the area directly behind each ear and along the base of the skull. Swelling here often indicates scalp or ear problems.

Armpits (Axillary Nodes): Raise one arm slightly and place the opposite hand high in the armpit with fingers pointing toward the ceiling. Press gently against the chest wall and slowly bring your fingers down. Repeat on the other side.

Groin (Inguinal Nodes): Lying down or standing, feel along the crease where your leg meets your torso. Small, soft, movable nodes are often normal in this location.