Step 4: Read and complete the decision guide to learn more about your symptoms.
Swollen Glands (General)
If you have swelling in one armpit, it could either be a swollen lymph node or an abscess.
An abscess is a pocket of infection that can develop around infected hairs in the armpit or groin. An abscess is usually red and very tender to touch.
Is the swelling in your armpit red and painful?