L04.2: Acute lymphadenitis of upper limb

One or more of the lymph nodes in your armpit or arm have suddenly become inflamed.

The lymph nodes are small bean-shaped objects. They are found throughout the body. Lymph nodes filter the tissue fluid. They are part of the defense system. Our lymph nodes contain certain immune cells. The immune cells can identify and attack pathogens or changed body cells, for example.

A lymph node gets inflamed when, for example, the body has been infected by pathogens. If immune cells in the lymph node work harder than usual due to an inflammation, the affected lymph nodes swell up.

Lymph nodes in your armpit or arm have suddenly swollen up. Applying pressure on the affected site is usually painful. The affected site may also appear red. Pus may also have collected there.

Additional indicator

On medical documents, the ICD code is often appended by letters that indicate the diagnostic certainty or the affected side of the body.

  • G: Confirmed diagnosis
  • V: Tentative diagnosis
  • Z: Condition after
  • A: Excluded diagnosis
  • L: Left
  • R: Right
  • B: Both sides

Further information


This information is not intended for self-diagnosis and does not replace professional medical advice from a doctor. If you find an ICD code on a personal medical document, please also note the additional indicator used for diagnostic confidence.
Your doctor will assist you with any health-related questions and explain the ICD diagnosis code to you in a direct consultation if necessary.


Provided by the non-profit organization “Was hab’ ich?” gemeinnützige GmbH on behalf of the Federal Ministry of Health (BMG).