When should you see a doctor about swollen lymph nodes?

Lymph nodes often enlarge while the immune system responds to an infection near them. They may be tender and appear in the neck, armpit, or groin. Other causes are possible, including inflammatory conditions and cancers affecting lymphatic or blood-forming tissues. Swollen nodes can occur with head and neck cancer, lymphoma, leukaemia, or cancer that has spread, but swelling alone cannot show which cause is present.

Note when the swelling started, where it is, whether it is painful, and whether it changes in size. Record recent infections, dental problems, skin injuries, medicines, fevers, sweating at night, tiredness, or weight changes. A clinician may examine several lymph-node areas and decide whether blood tests, imaging, or a sample is needed. Do not repeatedly press or massage a lump, as this can make it sore.

Seek urgent help if swollen nodes are accompanied by trouble breathing or swallowing, rapidly increasing neck swelling, severe weakness, confusion, or a high fever with marked illness. If you are receiving chemotherapy or another treatment that affects immunity, contact your oncology team promptly for a new fever or rapidly worsening symptoms.

Ask which features matter most, whether nearby nodes need examination, which tests are appropriate, and how to recognise changes that require faster review.