Which swollen lymph nodes should I be worried about?

The single most concerning location at any size is the supraclavicular area — the soft triangle just above the collarbone. A node here can drain the chest, lungs, or abdomen and is associated with a high rate of serious underlying pathology. Other concerning features include: nodes that persist beyond four to six weeks; nodes that are hard, fixed, or matted together; nodes larger than 2 cm or growing; painless nodes (reactive nodes are often tender); B-symptoms — drenching night sweats, unexplained fever, or losing 10% of body weight over six months; and enlarged spleen or liver on examination. Young adults with posterior cervical lymphadenopathy after a sore throat and fatigue are most often experiencing glandular fever.

What does it mean if my lymph nodes are reactive?

Reactive means the nodes are responding to an infection or inflammation nearby — they fill with immune cells doing their job. Common causes are viral upper respiratory tract infections, dental infections, skin infections, and glandular fever (Epstein-Barr virus). Reactive nodes are typically soft, tender, mobile, smaller than 2 cm, and appear alongside other signs of infection. They almost always shrink over two to six weeks. No specific treatment is usually needed beyond treating the underlying infection if one is identified. A watchful waiting approach with a safety-net review at four to six weeks is appropriate for nodes that look reactive.

Why is an excisional biopsy recommended rather than a fine-needle aspiration for suspected lymphoma?

Lymphoma diagnosis depends on examining the entire microscopic architecture of the lymph node — how cells are arranged, whether certain zones are preserved, and detailed immunological markers. Fine-needle aspiration (FNA) obtains individual cells but cannot show this architecture; the pathologist cannot reliably tell whether lymphoma is present or classify its type. A core biopsy (a larger needle) can sometimes substitute if the node is difficult to access, but an excisional biopsy — surgically removing the entire node — remains the gold standard recommended by the Cancer Council Australia Optimal Cancer Care Pathway and major haematology guidelines.

What blood tests should be done for lymphadenopathy?

For any unexplained or persistent lymphadenopathy, the standard initial blood panel includes a full blood count with film (to look for abnormal white cells, atypical lymphocytes, or blasts), inflammatory markers (ESR and CRP), LDH (a tumour burden marker), liver and kidney function, and calcium. Serology for Epstein-Barr virus or a monospot test is important in adolescents and young adults with posterior cervical nodes and fatigue. HIV serology is recommended for all adults with unexplained generalised lymphadenopathy. Syphilis serology is added when STI exposure is possible. A chest X-ray is appropriate for adults with persistent or generalised lymphadenopathy to look for mediastinal lymphoma, sarcoidosis, or TB.

When will I need a scan for swollen lymph nodes?

Ultrasound is the first imaging step for peripheral lymph nodes (neck, armpit, or groin) — it characterises the size, shape, blood flow, and whether the normal internal structure (hilum) is preserved, helping distinguish reactive from abnormal nodes. CT scanning of the chest, abdomen, and pelvis is added when nodes persist or are associated with B-symptoms, suspected lymphoma, or systemic features. PET-CT is a specialist-ordered staging tool used after a lymphoma diagnosis is confirmed, not as an initial investigation. MRI is preferred for head and neck cancer assessment and when radiation is best avoided.

Do children get concerning lymph nodes?

Enlarged cervical lymph nodes are extremely common in children, most often reactive to viral upper respiratory infections, and the vast majority need no investigation beyond watchful waiting. However, bacterial lymphadenitis — tender, warm, and sometimes fluctuant — caused by Staphylococcus aureus or Group A Streptococcus requires antibiotic treatment with flucloxacillin or cephalexin and incision and drainage if fluctuant. Kawasaki disease should be considered in a child with fever for five or more days and one or more additional features including a large cervical node over 1.5 cm. Rapid-onset abdominal or jaw node enlargement in a child is a red flag for Burkitt lymphoma.

Lymphadenopathy

Swollen lymph nodes: when to watch and when to act urgently

By Dr HB Lo, FACRRM Reviewed 5 July 2026 10 min read

Lymph node enlargement is extremely common in general practice — the vast majority are reactive to a recent infection and resolve within four to six weeks without specific treatment.

The first question is localised versus generalised. The second is reactive versus concerning: hard, fixed, or rubbery nodes larger than 2 cm, persisting beyond six weeks, painless, supraclavicular, or accompanied by B-symptoms — fever, drenching night sweats, or unexplained weight loss — need urgent investigation.

Excisional biopsy — not fine-needle aspiration alone — is the gold standard for suspected lymphoma because it preserves nodal architecture for pathology.

What lymphadenopathy actually is

A lymph node is a small bean-shaped immune organ — there are around 600 throughout the body — that filters lymph fluid and mounts immune responses to nearby infection or injury. Lymphadenopathy simply means one or more nodes are enlarged beyond their normal size: above 1 cm in most regions, above 0.5 cm at the epitrochlear (inner elbow), and above 1.5 cm in the groin, where small palpable nodes without pathology are common.

In Australian general practice, swollen lymph nodes are one of the most frequent presentations. The RACGP Australian Journal of General Practice (2023) summarises that the overwhelming majority of lymphadenopathy in general practice is reactive — driven by common viral and bacterial infections — and resolves spontaneously. The clinical challenge is recognising the minority that harbour serious pathology: lymphoma, leukaemia, metastatic cancer, tuberculosis, or HIV.

The two fundamental questions at the first visit are: (1) is this localised (one anatomical region) or generalised (two or more non-contiguous regions)? and (2) are the features reactive or concerning?

A. Core clinical — the AU general practice framework

Reactive versus concerning: the decision framework

Bazemore and Smucker (Am Fam Physician 2002) and the RACGP AJGP 2023 article provide consistent guidance on distinguishing reactive from concerning lymphadenopathy:

Feature	Reactive	Concerning
Size	Under 2 cm	2 cm or larger, or growing
Duration	Under 4–6 weeks, resolving	Persists beyond 4–6 weeks
Tenderness	Often tender	Painless
Consistency	Soft, rubbery	Hard, rubbery, matted, fixed
Mobility	Mobile	Fixed to skin or deep structures
Location	Anterior cervical, inguinal	Supraclavicular at any size; epitrochlear
B-symptoms	Absent	Fever, drenching night sweats, weight loss ≥10% in 6 months

Supraclavicular lymphadenopathy is always concerning, at any size. A left supraclavicular node (Virchow’s node / Troisier sign) drains from the abdomen and signals possible gastric, pancreatic, ovarian, or testicular malignancy. A right supraclavicular node drains from the mediastinum and lungs. Both warrant urgent investigation.

Epitrochlear nodes (at the inner elbow, draining the forearm and hand) are almost always abnormal when palpable — important causes include cat-scratch disease, secondary syphilis, HIV, sarcoidosis, and lymphoma.

Anatomy and drainage — where the node is matters

Lymph nodes follow a predictable drainage map. Cervical nodes (anterior and posterior chains) drain the head, neck, scalp, and posterior pharynx — the most common reactive site after viral upper respiratory tract infections and glandular fever. Axillary nodes drain the upper limb, breast, and chest wall — any persistent axillary node in a woman needs breast pathology excluded. Inguinal nodes drain the lower limb, perineum, and lower abdomen — sexually transmissible infections, lower limb infections, and lower genital tract cancers all present here.

History — key domains

The history should cover:

Lump features — onset, growth, painful versus painless, fluctuation in size, whether alcohol worsens the ache (alcohol-induced pain in lymph nodes is a rare but classic pointer to Hodgkin lymphoma)
B-symptoms — fever, drenching night sweats (soaking the sheets), weight loss of 10% or more over six months, pruritus
Local source — recent sore throat, dental problem, skin infection, ear infection
Travel — TB-endemic regions, areas with Q fever, schistosomiasis, malaria exposure
Animal exposures — cat scratch or bite (Bartonella), livestock contact (Q fever, brucellosis)
Sexual history — new partners, STI exposure; inguinal nodes are common in syphilis, genital herpes, and lymphogranuloma venereum
Medications — phenytoin, carbamazepine, allopurinol, lamotrigine, and vancomycin can cause DRESS syndrome (drug reaction with eosinophilia and systemic symptoms) — a serious drug reaction presenting with lymphadenopathy, fever, rash, and liver injury; the offending drug is typically started 2–8 weeks before symptoms
HIV risk factors — ask all patients with unexplained generalised lymphadenopathy

Examination

All peripheral lymph node groups should be systematically examined and documented: occipital, post-auricular, pre-auricular, submental, submandibular, cervical (anterior and posterior chains), supraclavicular, axillary, epitrochlear, inguinal, and popliteal. Document size in millimetres (not “small” or “large”), consistency, mobility, and tenderness. Examine the spleen, liver, skin (full scalp-to-sole examination for melanoma, infections), oropharynx and dentition, and breasts in women with axillary nodes.

Initial investigations

Per RACGP AJGP 2023, the standard first-line panel for unexplained or persistent lymphadenopathy includes:

Full blood count with film — lymphocytosis in viral illness and chronic lymphocytic leukaemia; atypical lymphocytes in glandular fever; blasts in acute leukaemia; cytopenia suggesting marrow infiltration
ESR and CRP — marked elevation raises concern for lymphoma, myeloma, or systemic inflammation
LDH — tumour burden marker; elevated in lymphoma and leukaemia
Liver function, renal function, calcium — baseline; hypercalcaemia in some lymphomas and sarcoidosis
Epstein-Barr virus (EBV) serology or monospot — particularly in adolescents and young adults with cervical posterior triangle nodes, fatigue, and sore throat; note monospot sensitivity is only ~50% in the first week — if negative, repeat or send EBV serology
HIV serology — all patients with unexplained generalised lymphadenopathy
Syphilis serology — when STI exposure possible
Chest X-ray — for all adults with persistent or generalised lymphadenopathy; identifies mediastinal lymphoma, sarcoidosis, or pulmonary tuberculosis

Targeted additions based on history: CMV serology if EBV-negative; toxoplasmosis serology with cat exposure; QuantiFERON Gold Plus (IGRA) and Mantoux for TB contacts or travel; Bartonella henselae serology for cat-scratch; hepatitis B and C when risk factors present.

B. Key syndromes to know

Infectious mononucleosis (glandular fever, EBV)

The classic presentation in adolescents and young adults: severe sore throat, fever, profound fatigue, posterior cervical and often generalised lymphadenopathy, splenomegaly in 50%, and palatal petechiae. Atypical lymphocytes appear on the blood film. The monospot (Paul-Bunnell) is positive in most cases by the second week. Amoxicillin must be avoided — it causes a confluent maculopapular rash in approximately 80% of EBV-infected patients (this is not a true allergy). Contact sports should be avoided for four weeks due to splenic rupture risk. The illness is self-limiting and managed symptomatically.

Tuberculosis lymphadenitis (scrofula)

The most common form of extrapulmonary tuberculosis worldwide, affecting the cervical nodes most frequently. It presents as chronic, painless, firm cervical swelling that may become fluctuant, with sinus formation over time. Diagnosis requires biopsy with AFB culture and PCR. Tuberculosis is a notifiable disease in all Australian states and territories — notify the state TB unit immediately. Treatment follows the Australian and New Zealand TB Guidelines (NTAC 2024).

HIV

Acute HIV seroconversion presents with a mononucleosis-like illness: fever, sore throat, generalised lymphadenopathy, and rash. HIV antigen and RNA are detectable from day 10–14; antibody testing may be negative in this window. Any person with unexplained generalised lymphadenopathy should be offered HIV testing. Chronic HIV causes persistent generalised lymphadenopathy and is associated with increased rates of non-Hodgkin lymphoma. ASHM guidelines provide the Australian management framework.

Lymphoma

Hodgkin lymphoma characteristically presents in young adults (bimodal peak at 15–35 and then 50+) with painless cervical or supraclavicular lymphadenopathy, sometimes with mediastinal mass on chest X-ray, B-symptoms, and pruritus. The rare finding of alcohol-induced lymph node pain is classic for Hodgkin. Non-Hodgkin lymphoma encompasses a diverse group — diffuse large B-cell, follicular, mantle cell, and others — often presenting with rapidly enlarging peripheral nodes or abdominal masses. Pathological diagnosis by excisional biopsy is essential.

Cat-scratch disease (Bartonella henselae)

Regional lymphadenopathy at the site draining a cat scratch or bite, usually in the axilla or cervical region, appearing 1–3 weeks after inoculation. The node is tender and may suppurate. Serology (IgG titre ≥1:256) confirms the diagnosis. Most cases are self-limiting; azithromycin shortens the course. eTG Antibiotic provides the antibiotic guidance.

C. Tissue diagnosis — excisional biopsy is the standard

The Cancer Council Australia Optimal Cancer Care Pathway for Lymphoma (2024) and Lugo-Zamudio et al. (Ann Hematol 2020) both establish that excisional biopsy is the gold standard for suspected lymphoma. It preserves the nodal architecture required for immunohistochemistry, flow cytometry, cytogenetics, and molecular testing — information that cannot be obtained from fine-needle aspiration (FNA). FNA is useful for confirming metastatic carcinoma but is inadequate for primary lymphoma classification. Core biopsy (≥18 gauge, multiple cores) is an acceptable alternative when excision is technically difficult.

When lymphoma is suspected, discuss with the pathologist before the procedure — fresh tissue for flow cytometry may be requested. The largest and most abnormal accessible node should be chosen; inguinal nodes are generally avoided because they are commonly reactive regardless of proximal pathology.

Ultrasound-guided core biopsy is MBS-rebatable for accessible nodes; excisional biopsy is performed by a surgeon under MBS item 30075.

D. Australian operations

Referral pathways

Clinical scenario	Referral	Urgency
Suspected lymphoma	Haematology or oncology	Urgent (within 2 weeks)
Suspected head and neck cancer	ENT surgeon	Urgent
Suspected breast cancer (axillary node)	Breast surgeon or clinic	Urgent
Suspected metastatic melanoma	Melanoma unit	Urgent
Positive HIV result	Sexual health / ASHM s100 prescriber	Same-day linkage
Suspected tuberculosis	State TB unit (notifiable)	Urgent
Sarcoidosis	Respiratory physician	Routine
Reactive cervical nodes, child	Watchful waiting / paediatrician if complicated	Routine

The NICE NG12 suspected cancer referral guideline (2023) recommends urgent referral for unexplained lymphadenopathy persisting beyond six weeks — Australian practice is aligned with this threshold.

MBS items relevant to lymphadenopathy workup

Full blood count (item 65070), blood film morphology (item 65072), LDH (item 66821), ESR and CRP (item 65126), EBV serology (item 66518), HIV serology (item 69384), syphilis serology (item 69323), hepatitis B and C serology (item 69378), toxoplasmosis serology (item 69477), chest X-ray (item 58503), CT neck (item 56401), CT chest and abdomen/pelvis (item 56301 and 56401), lymph node ultrasound (item 55054), FNA cytology (item 73053), and excisional lymph node biopsy (item 30075).

ATSI-specific considerations

Tuberculosis rates are higher in some Aboriginal and Torres Strait Islander communities, particularly remote areas — the threshold for IGRA testing and chest X-ray should be lower. Streptococcal skin infection is prevalent and a common cause of reactive cervical lymphadenopathy. Cultural safety, involving an Aboriginal Health Worker where available, and linkage to specialist care with appropriate support are essential.

E. Special populations

Children and adolescents. Reactive cervical lymphadenopathy is near-universal after viral upper respiratory infections in children and requires only watchful waiting with safety-netting. Bacterial lymphadenitis (warm, tender, fluctuant, unilateral) responds to flucloxacillin or cephalexin per eTG Antibiotic and RCH Melbourne Cervical Lymphadenitis CPG (2024); incision and drainage for fluctuant cases. Kawasaki disease must be considered in a febrile child with a cervical node over 1.5 cm and four or more additional Kawasaki features. Burkitt lymphoma — rapidly growing jaw or abdominal mass — is an oncological emergency requiring same-day referral and tumour lysis prophylaxis.

Pregnancy. Full investigation is appropriate, but CT should be avoided where possible. Ultrasound and MRI are the preferred imaging modalities. Lymphoma in pregnancy is treatable; management requires a multidisciplinary obstetric haematology team.

Immunocompromised patients. People on immunosuppression, with HIV, or post-transplant have a markedly increased risk of lymphoma (particularly EBV-driven post-transplant lymphoproliferative disease) and opportunistic infections causing lymphadenopathy. A lower threshold for investigation and biopsy applies.

When to escalate

Refer to the emergency department immediately for:

Suspected acute leukaemia — blasts on blood film, pancytopenia
DRESS syndrome — stop the offending drug and admit; multi-organ involvement (liver, kidneys) can be life-threatening
Septic lymphadenitis with systemic toxicity

Refer urgently (within days to 2 weeks) for:

Supraclavicular lymphadenopathy at any size
Persistent lymphadenopathy with B-symptoms (fever, drenching night sweats, weight loss)
Hard, fixed, or rapidly growing nodes
Abnormal blood film (blasts, lymphocytosis with atypical morphology)
Positive HIV result — same-day specialist linkage

What this article is and is not

This is general health information drawn from current Australian general practice guidelines — RACGP Australian Journal of General Practice, Therapeutic Guidelines, the Cancer Council Australia Optimal Cancer Care Pathways, ASHM HIV guidelines, and the National TB Advisory Committee guidelines. It is not personal medical advice and does not create a doctor–patient relationship. Decisions about investigation, biopsy, and referral are made with your own general practitioner and specialist.

For Australian consumer information: HealthDirect — swollen lymph nodes, Better Health Channel — lymph nodes and swollen glands, Lymphoma Australia, Leukaemia Foundation.

Sources cited

Frequently asked questions

Which swollen lymph nodes should I be worried about?

The single most concerning location at any size is the supraclavicular area — the soft triangle just above the collarbone. A node here can drain the chest, lungs, or abdomen and is associated with a high rate of serious underlying pathology. Other concerning features include: nodes that persist beyond four to six weeks; nodes that are hard, fixed, or matted together; nodes larger than 2 cm or growing; painless nodes (reactive nodes are often tender); B-symptoms — drenching night sweats, unexplained fever, or losing 10% of body weight over six months; and enlarged spleen or liver on examination. Young adults with posterior cervical lymphadenopathy after a sore throat and fatigue are most often experiencing glandular fever.
What does it mean if my lymph nodes are reactive?

Reactive means the nodes are responding to an infection or inflammation nearby — they fill with immune cells doing their job. Common causes are viral upper respiratory tract infections, dental infections, skin infections, and glandular fever (Epstein-Barr virus). Reactive nodes are typically soft, tender, mobile, smaller than 2 cm, and appear alongside other signs of infection. They almost always shrink over two to six weeks. No specific treatment is usually needed beyond treating the underlying infection if one is identified. A watchful waiting approach with a safety-net review at four to six weeks is appropriate for nodes that look reactive.
Why is an excisional biopsy recommended rather than a fine-needle aspiration for suspected lymphoma?

Lymphoma diagnosis depends on examining the entire microscopic architecture of the lymph node — how cells are arranged, whether certain zones are preserved, and detailed immunological markers. Fine-needle aspiration (FNA) obtains individual cells but cannot show this architecture; the pathologist cannot reliably tell whether lymphoma is present or classify its type. A core biopsy (a larger needle) can sometimes substitute if the node is difficult to access, but an excisional biopsy — surgically removing the entire node — remains the gold standard recommended by the Cancer Council Australia Optimal Cancer Care Pathway and major haematology guidelines.
What blood tests should be done for lymphadenopathy?

For any unexplained or persistent lymphadenopathy, the standard initial blood panel includes a full blood count with film (to look for abnormal white cells, atypical lymphocytes, or blasts), inflammatory markers (ESR and CRP), LDH (a tumour burden marker), liver and kidney function, and calcium. Serology for Epstein-Barr virus or a monospot test is important in adolescents and young adults with posterior cervical nodes and fatigue. HIV serology is recommended for all adults with unexplained generalised lymphadenopathy. Syphilis serology is added when STI exposure is possible. A chest X-ray is appropriate for adults with persistent or generalised lymphadenopathy to look for mediastinal lymphoma, sarcoidosis, or TB.
When will I need a scan for swollen lymph nodes?

Ultrasound is the first imaging step for peripheral lymph nodes (neck, armpit, or groin) — it characterises the size, shape, blood flow, and whether the normal internal structure (hilum) is preserved, helping distinguish reactive from abnormal nodes. CT scanning of the chest, abdomen, and pelvis is added when nodes persist or are associated with B-symptoms, suspected lymphoma, or systemic features. PET-CT is a specialist-ordered staging tool used after a lymphoma diagnosis is confirmed, not as an initial investigation. MRI is preferred for head and neck cancer assessment and when radiation is best avoided.
Do children get concerning lymph nodes?

Enlarged cervical lymph nodes are extremely common in children, most often reactive to viral upper respiratory infections, and the vast majority need no investigation beyond watchful waiting. However, bacterial lymphadenitis — tender, warm, and sometimes fluctuant — caused by Staphylococcus aureus or Group A Streptococcus requires antibiotic treatment with flucloxacillin or cephalexin and incision and drainage if fluctuant. Kawasaki disease should be considered in a child with fever for five or more days and one or more additional features including a large cervical node over 1.5 cm. Rapid-onset abdominal or jaw node enlargement in a child is a red flag for Burkitt lymphoma.

Source quality

Sources grouped by evidence tier. AU primary tier first; international where AU is silent or lagging; named-author reconstruction where guidelines have not yet caught up. How tiers work.