Causes of Swollen Lymph Nodes and Which Medical Specialty to Consult
Swollen lymph nodes are a common health concern that can signal anything from a minor infection to a more serious underlying condition. These small, bean-shaped glands are part of the body's immune system and are distributed throughout areas like the neck, armpits, and groin. When they become enlarged, it often indicates that the body is fighting off an infection or responding to another medical issue. If you notice swollen lymph nodes, the first point of contact should typically be a general surgeon or a specialist in internal medicine, depending on the symptoms and location.
Common Causes of Lymph Node Enlargement
Lymph nodes act as filters for harmful substances and play a key role in immune defense. Their swelling—also known as lymphadenopathy—can stem from various causes, ranging from mild infections to more severe diseases. Understanding these triggers helps determine the appropriate course of action and when to seek medical evaluation.
1. Infections and Inflammatory Conditions
Infections are the most frequent cause of swollen lymph nodes. When bacteria, viruses, or other pathogens enter the body, nearby lymph nodes respond by increasing in size as immune cells multiply to fight the invaders. This is especially noticeable in superficial areas such as the neck (cervical), underarms (axillary), and groin (inguinal).
For example, conditions like strep throat, tonsillitis, upper respiratory infections, or dental abscesses often lead to tender, movable lymph nodes in the neck. These nodes may exceed 1 cm in diameter—sometimes reaching up to 2 cm—but usually retain their typical oval shape and soften as the infection resolves. Viral illnesses such as mononucleosis or even common colds can produce similar effects.
While most infection-related swelling subsides within a few weeks, persistent enlargement beyond two to four weeks warrants further investigation.
2. Malignancies and Cancer-Related Lymphadenopathy
Another critical reason for enlarged lymph nodes is cancer. Certain tumors, particularly breast cancer, melanoma, lymphoma, and leukemia, can spread to or originate within the lymphatic system. For instance, women who detect a firm, painless lump in the armpit should consider the possibility of metastatic breast cancer, as the axillary lymph nodes serve as sentinel sites for tumor cell migration.
Unlike infection-induced swelling, cancer-related lymph nodes tend to be hard, fixed in place, and grow progressively without signs of inflammation. They may also appear in multiple regions of the body—a sign often associated with systemic diseases like lymphoma.
Early detection is crucial. Anyone experiencing unexplained, long-lasting lymph node enlargement—especially if accompanied by weight loss, night sweats, or fatigue—should consult a healthcare provider promptly for diagnostic tests such as ultrasound, blood work, or biopsy.
When to Seek Medical Attention
While occasional lymph node swelling is normal during illness, certain red flags require immediate evaluation:
- Lymph nodes larger than 1.5 cm that persist for more than 2–4 weeks
- Nodes that feel hard, irregular, or immobile
- Swelling without any apparent infection
- Accompanying symptoms like fever, chills, unintended weight loss, or night sweats
In such cases, visiting a general surgeon or being referred to a hematologist or oncologist may be necessary for proper diagnosis and management.
Diagnostic Approach and Next Steps
Doctors typically begin with a thorough physical exam and patient history. Imaging studies like ultrasound or CT scans help assess the size, shape, and structure of the nodes. Blood tests can reveal signs of infection or autoimmune disorders, while a lymph node biopsy may be performed if malignancy is suspected.
Treatment depends entirely on the underlying cause—antibiotics for bacterial infections, antivirals where appropriate, or specialized therapies for cancer. Never ignore persistent lymph node changes; timely intervention leads to better outcomes.