Experiencing a tender lump or swelling under your arm can be concerning. Often, this is due to inflamed or blocked sweat glands—a condition distinct from swollen lymph nodes. The armpits contain two types of sweat glands, but the issue usually involves the apocrine glands , which become active during puberty and produce a thicker sweat.
The most common causes of swollen sweat glands in the armpits include: swollen sweat glands in armpits