Swollen Lymph Nodes: Causes, Pain, and When to See a Doctor

Lymphadenopathy (swollen nodes) is common and usually reactive, not malignant.

Common Benign Causes

• Infections: Viral (URI, EBV, CMV, HIV), bacterial (strep, staph, TB, cat-scratch), fungal.
• Inflammatory: Autoimmune (SLE, RA), Kawasaki, sarcoidosis.
• Medications: Phenytoin, allopurinol, vaccines (transient).
• Local irritation: Scalp dermatitis → occipital nodes; dental caries → submandibular.

Malignancy Red Flags

• Hard, fixed, matted, non-tender nodes
• Size >2 cm (or >1 cm supraclavicular)
• Progressive enlargement >2–4 weeks
• Constitutional symptoms: fever, night sweats, weight loss
• Supraclavicular location (Virchow's node = GI malignancy)

Pain ≠ Benign, Painless ≠ Malignant

Tender nodes often inflammatory; painless nodes can be malignant — but many exceptions. Clinical context and duration matter more than pain alone.

Workup

1. History: exposure, travel, medications, systemic symptoms.
2. Exam: location, size, consistency, mobility, tenderness.
3. If localized + likely infectious: observe 2–4 weeks.
4. If persistent, supraclavicular, or red flags: CBC, imaging (US/CT), excisional biopsy (gold standard).

Most resolve spontaneously. Persistent or concerning nodes need biopsy.