Lymph Node
A small bean-shaped immune organ that filters lymph fluid and houses white blood cells.
What it means
Lymph nodes are small organs of the immune system, clustered in the neck, armpits, groin, chest and abdomen. They filter lymph fluid draining from the tissues and house the white cells that mount immune responses.
Enlargement is termed lymphadenopathy. In the great majority of cases this is a normal immune response to nearby infection — tender, mobile nodes appearing with a sore throat and settling within weeks.
Nodes are also the route by which cancers spread, which is why they are sampled during cancer surgery and staging.
In practice
Reported on examination and imaging, described by site, size, tenderness and mobility. "Shotty" describes multiple small mobile nodes, a common and benign finding.
Sentinel node biopsy identifies the first node draining a tumour.
Why it matters
Reassuring features are tenderness, mobility, small size, and resolution within a few weeks alongside an obvious infection.
Features warranting investigation are a node that is hard, fixed, painless, larger than about 2cm, or persisting beyond six weeks — particularly with night sweats, weight loss or fever.
Clinically reviewed by Dr Mohammad Zubair Khan, GMC 7563469
Last reviewed
August 30, 2026